Gardening Tips

This page lists all of our gardening tips, sorted alphabetically by title. To view lists of tips by month or topic, visit our Tips & Events web page.

Ailing Ornamental Trees

If you have an ailing tree, here are some questions you can ask yourself to begin diagnosing the problem: is the entire canopy of the tree affected? If the answer is yes, you can reasonably guess that something is wrong below the soil. A lack of nutrients (refer to the UC Pest Note on Mineral Deficiencies) will likely cause the leaves to either die (necrosis) or lose color (chlorosis). Too much or too little water will also cause foliage problems (See UC Pest Note on Poor Water Management, Poor Drainage).

If only parts of the tree are affected, it is likely your problem is above ground. Is there a pattern to the distress? You can rule out or suspect sunscald by determining which side of the tree faces the harshest sun (UC Pest Note on Sunburn).

What kind of tree is it? Is there new growth? If there is, that’s a great sign that a single event rather than an ongoing problem distressed your tree. The UC IPM website will direct you to species-specific pests and disorders to begin diagnosing your tree's ailments.

Months applicable: August, Any month

Tags: Abiotic Disorders, Disease, IPM, Trees & Shrubs, Waterwise Tips

Almond and Walnut Harvest

Almonds are harvested when the shell is cracked and brown. Freeze nuts for 1-2 weeks to kill resident worms, store nuts in plastic bags to prevent re-infestation, and spray the tree with fixed copper during or after leaf fall but before rains start to reduce damage from shot hole fungus.

Walnuts are fully mature when the green hull begins to break away from the shell. Harvest by polling or shaking the tree. Remove the green hulls, then freeze nuts in the shell to kill any resident worms. Store in plastic.

Months applicable: October

Tags: Disease, Fruits & Nuts, IPM, Techniques

Aloe Plants

The Aloe genus contains hundreds of different species, with Aloe vera being the most commonly known because of its medicinal uses. They are all succulents, and the majority have spines along the leaf edges. Their dramatic stalks of flowers are often visited by hummingbirds. Most species flower yearly; however, some types bloom more frequently, even year-round. The plants need little care, but because they come in all sizes, make sure you know how big a particular species will grow before you plant it. UC Davis has a Botanical Notes publication that includes notes about some of their favorites.

You can see their dramatic stalks of flowers here. Photo: Aloe flowers, clockwise from upper left: Aloe ferox, Aloe striata (coral aloe), Aloe polyphylla (spiral aloe), Aloe ‘Rooikappie’

Months applicable: Any month

Tags: House Plants, Ornamental Plants, Techniques, Waterwise Plants, Waterwise Tips

Amaryllis or is it Hippeastrum?

The showy red Amaryllis (more correctly called Hippeastrum) is a great bulb for growing indoors if you can’t wait for your outdoor bulbs to bloom in spring. Choose a pot just slightly larger than the bulb. Plant it in loose potting soil with a third of the bulb sticking up above the soil surface. Keep moist, but not so wet as to rot the bulb. The University of Minnesota Extension has information on general care and how to control blooming.

Months applicable: January, December

Tags: Container Gardening, Ornamental Plants

Ant Control

On outdoor and sometimes indoor plants, ants protect and care for honeydew-producing insects such as aphids, soft scales, whiteflies, and mealybugs, increasing damage from these pests.

Ant management requires diligent efforts and the combined use of mechanical, cultural, sanitation, and often chemical control methods. It is unrealistic and impractical to attempt to totally eliminate ants from an outdoor area. Focus your management efforts on excluding ants from buildings or valuable plants and eliminating their food and water sources. Reducing outdoor sources of ants near buildings will reduce the likelihood of ants coming indoors.

Ants on Trees and Shrubs

When numerous ants are found on plants, they are probably attracted to the sweet honeydew deposited on the plants by honeydew-producing insects such as aphids or soft scales. Ants may also be attracted up into trees or shrubs by floral nectar or ripening or rotten sweet fruit. These ants can be kept out by banding tree trunks with sticky substances such as Tanglefoot. Trim branches to keep them from touching structures or plants so that ants are forced to try to climb up the trunk to reach the foliage.

When using Tanglefoot on young or sensitive trees, protect them from possible injury by wrapping the trunk with a collar of heavy paper, duct tape, or fabric tree wrap and coating this with the sticky material. Check the coating every one or two weeks and stir it with a stick to prevent the material from getting clogged with debris and dead ants, which will allow ants to cross. Ant stakes with bait can also be used around trees.

For more information about what ant baits and insecticides to use, please consult the UC Pest Note on Ants.

Months applicable: June, July, August, Any month

Tags: IPM, Invertebrates

Aphids

Have you noticed that different plants attract aphids of different colors and shapes? Once you’re done admiring nature, you may want to take action to protect your plants. Aphids are classified as sucking insects, which means that they suck the juices right out of plants. They take the nutrients needed for plant growth, and the plant will start to get weak and possibly die. If you monitor your garden regularly and find aphids when their population is still small, you may be able to simply knock or hose them off the plant or prune out the infected part of the plant. When aphid populations are large, nature can help you control them — beneficial insects will be attracted to eat the aphids.

You can encourage beneficial insects in your garden by including a variety of plants that flower at different times throughout the season. Avoid chemicals that kill good and bad indiscriminately. If ants are protecting the aphids in a plant, control the ants. Decide what population you will tolerate in your garden, and have patience because it can take time to establish a healthy ecosystem.

More information: Aphid management guidelines in English| Spanish

Months applicable: April, May

Tags: IPM, Invertebrates

Apple and Pear Harvest

The harvest for apples, and some varieties of pears (Bosc, Comice, Winter Nellis, and some Asian Pears), is likely coming to a close. When harvest is finished, irrigate and fertilize the trees as you have been. Clean up fallen leaves and fruit and discard to prevent apple scab and coddling moth.

Months applicable: October

Tags: Best Practices, Fruits & Nuts

Arboretum All-Stars

UC Davis, known for its horticulture expertise, has its own roster of 100 top-performing plants to consider for your garden. To make the cut, each Arboretum All-Star must be attractive for most of the year, thrive in California’s Mediterranean climate, and be thoroughly tested at the UC Davis Arboretum. To see them in person, take a day trip to the Arboretum – it’s open and free to the public. Or access their searchable database and find the perfect All-Stars for your specific garden conditions, along with planting plans and where to buy them.

More Information: UC Davis Arboretum All-Stars

 

Months applicable: April, October, Any month

Tags: Best Practices, Ornamental Plants, Waterwise Tips

Armillaria Root Rot

Mushrooms at the base of a tree could signal a problem with the tree. Armillaria is a fungus that can live in the soil for many years. It can rot the roots and cause leaves and branches to die and can eventually kill a plant. Another common term is Oak Root Fungus, although it affects many different species of trees and even some herbaceous plants. Often by the time the fruiting bodies (mushrooms) are visible, much damage has already been done. It feeds on both live and decaying wood. Cutting back a small section of bark can reveal white fan-shaped or black stringy fungus which aids in diagnosis. Keeping the plant healthy provides some defense. Fungi thrive in moist conditions, so do not overwater the area. Also, keep mulch and other plants away from the trunks of trees so as not to hold moisture against the crown (base). The best defense against this disease is to plant resistant varieties.

For information: Armillaria Root Rot

Months applicable: January, February, December

Tags: Abiotic Disorders, Disease, IPM

Armored Scale Control

These parasites suck the living sap from shrubs and trees. Armored scale insects are in the crawler stage in early summer (June). Armored scale has a hard stage that is very resistant to sprays. Control them during the crawler stage when they are soft and vulnerable. Spray with a horticultural (not dormant) oil, once a month for three months. See the UC Pest Note on Scales for important information about spraying.

Months applicable: June, Any month

Tags: IPM, Invertebrates

Asian Vegetables

Months applicable: February, March, April, May, June, September, October

Tags: Vegetables

Attracting Bees

Bees are pollination workhorses, increasing garden production. Many plants will not produce fruit unless flowers are pollinated. Colorful annuals, such as Cosmos, edible African Blue Basil, and Salvias attract bees. You can also allow herbs and other plants to flower to create bee-friendly landscapes.

The University of California at Davis has a garden dedicated to bees. The Honey Bee Haven website has more resources, including a list of plants they grow.

Months applicable: March, April, May, June, September, October

Tags: Beneficial Insects, Herbs, Ornamental Plants

Autumn Leaves - To Rake or Not to Rake

Fallen autumn leaves from healthy trees can provide valuable mulch, with the return of nutrients to the tree as the leaves slowly decompose. If you don’t like the look, you can add the leaves to the compost pile and later spread the compost under the tree. Diseased leaves should be put out with yard waste recycling to avoid spreading disease in your garden.

Months applicable: November

Tags: Best Practices, Garden Basics, Trees & Shrubs

Avocado Leaves

Avocado leaves can give you clues about the health of your tree. For example, if you find mature avocado leaves turning yellow, the "problem" might be no problem at all. That's what avocado leaves look like when they get old. Read more on how to "read" avocado leaves in this excellent "Reading Avocado Leaves" blog by San Diego Master Gardener Greg Alder. His article has many photos you can use for comparison for issues including mites, cold damage, sunburn, under- and over-watering, and more.

Months applicable: Any month

Tags: Disease

Avocados, Brown Spot

The brown patch that looks like a turtle's back is called Carapace Spot. It is corky and usually cracked into angular divisions. It is caused by rubbing or brushing of tender young fruit on leaves or stems in the wind, but the fruit is usually undamaged under the spot. Just cut out the spot. More pictures of avocado problems can be found on UC Pest Note On Causes of Avocado Fruit Damage.

Months applicable: April

Tags: Fruits & Nuts, IPM, Trees & Shrubs

Bagrada Bug

The Bagrada bug is a small (1/4”) stink bug that is most commonly found on vegetables in the Brassica family including cabbage, cauliflower, broccoli, kale, turnip, and mustard greens. Home gardeners should carefully inspect their plants and shipping containers prior to planting. A good time to inspect is right after watering when pests hiding in the space between the potting mix and the sides of the container may be flushed out and more easily detected. Plant seedlings late this month when they are big and robust. If you find nymphs on the plants, use insecticidal soap. See UC Pest Note on Bagrada Bug for further information.

Months applicable: October

Tags: IPM, Invertebrates

Bamboo

Bamboo has a reputation for spreading out of control, but not all varieties are classified as running bamboo. There are clumping bamboos that are easier to contain. Bamboo is grass, albeit one that can grow over fifty feet tall. Tall bamboo is often used as a privacy screen. It does best in full sun or partial shade. It is fairly drought tolerant and is an easy plant to grow. Deep barriers may be able to keep it from spreading. If planting in a container, check regularly to make sure the roots are not escaping from the drainage holes and thus growing beyond the pots into your yard or your neighbor’s. Foothill College in Los Altos Hills has a bamboo garden with over 80 varieties of bamboo if you’d like to see how many different ways bamboo can grow.

More information: Growing bamboo

Months applicable: Any month

Tags: Best Practices, Ornamental Plants

Bare Root Plants

Bare root plants are sold without any soil clinging to the roots making them easier and less expensive to transport; they'll do just fine in the garden as long as you don't let them dry out before planting. Because you can see the roots and can control how they're placed in the soil, it helps reduce the chances of root girdling problems later. Buy and plant early in the month while roots are still fresh.

The bare roots should be soaked from an hour to overnight (large plants) in a bucket of water before planting. Trim roots of broken, dead, or spongy bits and carefully pull the roots apart. Dig a hole that is fairly shallow and wide. Spread the roots out sideways and have the crown of the plant several inches above the soil level. This is necessary as the plant will settle down over time. Water in well but wait to fertilize until you see new shoots growing. Be sure to water regularly if the rains are sparse. Staking may not be necessary.

Trees aren't the only plants that are sold bare root. You can also plant bare-root asparagus, artichokes, rhubarb, berries, kiwifruit, horseradish, rhubarb, grapes, roses, strawberries, and iris in January.

More information: Planting Bare-Root Fruit Trees

Months applicable: January, February, March

Tags: Best Practices, Fruits & Nuts, Garden Basics, Ornamental Plants, Techniques, Trees & Shrubs

Bare Root Roses

Months applicable: January, February

Tags: Garden Basics, Ornamental Plants, Techniques

Bee Swarms

Bees are very active in warm weather. There is simply so much pollen and nectar to collect! Sometimes, a bee colony may swarm. If you see a swarm, don’t panic. As in any other time when working around bees, remain calm, move gently, and give them their space. Bees generally swarm when they are looking for a new home. Swarming bees are loaded with food and are not interested in stinging people. Contact the Bee Guild to have swarms removed.

Months applicable: May, June, July

Tags: Beneficial Insects, Best Practices

Birds

Birds can cause extensive damage to tree fruit crops. Unlike squirrels, birds are more likely to peck at one piece of fruit until it’s gone. If they are doing too much damage, netting over a tree can keep them away from the fruit. If you use visual repellents (such as Mylar streamers or noisemakers) to frighten them, be sure to vary the method so that the birds don’t become immune to the effects. Read the UC Pest Note on Birds on Tree Fruits and Vines for more information.

Months applicable: July, August, September

Tags: IPM, Techniques

Bitter Pit (Brown Spots) on Apples

Bitter pit is a physiological disorder that affects many varieties of apples. The condition develops after fruit has been picked. It is caused by low levels of calcium in fruit tissues which leads to small brown, sunken lesions that become dark and corky. Highly susceptible cultivars include Red Delicious, Granny Smith, Golden Delicious, Jonathan and Gravenstein. The UC Bitter Pit Pest Note recommends cultural practices for control.

For even more information, the UC Postharvest Technology Center website has grower information, including using calcium sprays starting in June.

Months applicable: August, September

Tags: Abiotic Disorders, Fruits & Nuts, IPM

Blueberries

Depending on the variety, you may be harvesting blueberries from your garden right now. Blueberries in stores often come from cooler climates like Oregon and Maine, yet there are several varieties of blueberries that do well in our warmer climate with a little extra care. They all need regular water and well-draining soil with a lower pH (more acidic) than our local native soil. Adding elemental sulfur is a good way to acidify the soil. Harvest blueberries on almost a daily basis, especially if you want to beat the birds and squirrels to the ripe berries. The blueberries are ready to eat when they are uniformly blue/purple, even on the bottom. They should come off easily with a slight tug. Annual post-harvest pruning will stimulate new growth and increase yield. Details are available in a video presentation by a local UC Master Gardener.

Months applicable: July

Tags: Fruits & Nuts

Bolting Lettuces

In garden terms, bolting means sending up a flower stalk, not desirable unless you plan to save seeds. Seed packets say lettuce matures in 60–80 days, but the timing also depends on the weather. In warm weather, lettuce matures and bolts much faster. In cool temperatures, seedlings grow more slowly but will still mature and bolt eventually. If the center of the lettuce starts to push upwards, that’s a clue that it’s starting to bolt. Another clue is if you tear a leaf and see milky sap instead of clear juices. Harvest as soon as you notice, before the leaves become unpleasantly bitter.

More information: Growing Lettuce

Months applicable: January, February, March, November, December

Tags: Best Practices, Vegetables

Bone Meal for Bulbs?

Bone meal has traditionally been used as a phosphorus source for flower bulbs, but you may want to reconsider. If your soil is healthy, you may not need it and you may be better off with a balanced fertilizer designed for bulbs or even nothing at all. The nutrient content of commercial bone meal is lower than in the past due to the cleaning process, and the bone smell may attract raccoons or dogs to dig up the bulbs.

Months applicable: November

Tags: Ornamental Plants, Soil

Boxwood Blight

Months applicable: August, September

Tags: Disease, IPM, Trees & Shrubs

Broccoli - Multiple Harvests

Did you know that most broccoli plants can give you multiple harvests? The first central head that they produce will be the largest and fullest. But after you harvest that one, the plant will start to produce lots of smaller heads, called side shoots. They sprout from buds in the leaf axils, where the leaves join the stem of the plant. You can keep harvesting these tender shoots, sometimes called broccolini or baby broccoli, for another 2 to 3 months.

More Information: Growing Broccoli

Months applicable: March, April, May, June, September, October, November, December

Tags: Best Practices, Vegetables

Brown Marmorated Stink Bug

Native to Eastern Asia, this pest was introduced to the United States in the 1990s and has been established in Santa Clara County. Some features to distinguish these bugs from other stink bugs are white stripes on the antennae, a blunt head shape, and smooth shoulder margins.

They feed and reproduce on a variety of plants and are particularly damaging to fruit. You can cut cosmetic damage off fruit and still eat the rest of the fruit. To keep out stink bugs, cover vegetable plants with row covers. You can pick the bugs off plants and squish them or knock them off into soapy water. They are attracted to light and can get into homes where if vacuumed up, they can stink up your vacuum bag.

Months applicable: March, April, May, June, July, August, September

Tags: Fruits & Nuts, IPM, Invertebrates, Vertebrates

Brown Rot on Apricot and Peaches

If your apricots or peaches had brown flesh last year, especially in the part surrounding the pit, they were probably infected with brown rot. It's a common fungal disease of stone fruit. You can spray with a copper spray at pink bud stage. A more important means of control is to remove affected fruit as soon as you notice it. The UC Pest Note on Brown Rot has more information.

Months applicable: March

Tags: Disease, Fruits & Nuts, IPM

Bug Patrol

Months applicable: July, August, September

Tags: Beneficial Insects, IPM, Invertebrates, Vertebrates

Burning & Stinging Nettles

Our gardens are pleasant places but not if you find burning nettle (Urtica urens) or stinging nettle (Urtica dioica) among your flowers or vegetables. You’ll know they are there if you brush against them and immediately feel a burning or stinging sensation. Leaves and stems are covered with hair-like tubes that inject an irritating substance when touched. Look for them in late fall and early spring. Remove them as soon as they appear, using gloves for protection. They can produce viable seeds in just five weeks and produce 1,500 seeds per plant. A thick layer of mulch or cover crops with dense canopies can help suppress germination.

More information: Burning & Stinging Nettles

Months applicable: March, April, October, November

Tags: Weeds

Cabbage Aphids

The grey-green cabbage aphid is often found on cool season vegetables. They prefer to feed on the youngest leaves and flowering parts and are often seen on cabbages, broccoli, and Brussels sprouts.

Hose them off plants or prune out infestations. Grow flowers in your vegetable garden to attract beneficial insects, which are their natural enemies.

See UC Pest Note on Aphids to identify and manage this insect.

Months applicable: October

Tags: IPM, Invertebrates, Vegetables

California Natives

Thinking of adding native California plants to your yard? New natives respond best to wet winter weather, which promotes the extensive root development needed for spring growth and the hot dry summer months ahead. Your next question may be what to plant. That depends on your planting site and the individual cultural requirements of the plant. To help, the California Native Plant Society has created a database where you can enter your address and find which plants do best in your neighborhood for the conditions in your yard, like sun or shade. The website even lists nurseries that carry California natives.

• How to plant California Natives
• Growing Natives Garden Tour
• Bloom! Garden Inspiration

Months applicable: January, February, March, December

Tags: Ornamental Plants, Waterwise Plants

California Poppies

The California poppy, seen on hillsides in late winter through early spring, can be grown in your own yard.

It can re-grow from a taproot or reseed itself rapidly throughout your garden and lawn, so consider whether this would be acceptable. If it is, seeds can be scattered now or with initial rains for vibrant color in a couple of months.

Months applicable: November

Tags: Ornamental Plants

Camellia Petal Blight

Camellias are beautiful except when the flowers turn a blotchy brown. This petal blight is caused by a fungus that continues to live in the soil once a plant is infected. To reduce outbreaks, pick off all infected flowers and dispose of them in green waste. Home composting is not hot enough to destroy the pathogen. After blooming, pick up any petal debris. Then spread fresh mulch around and beyond the bush (but keep the mulch a few inches away from the trunk).

More information: Camellias Petal Blight

Months applicable: March

Tags: Best Practices, Disease, IPM, Ornamental Plants

Camellias

Camellias can be planted in fall through spring. Since they bloom in winter, choosing a plant now will ensure that you know the color, shape, and size of the flowers with which you will live for many years. Camellias are not native to our area so may need some extra attention in order to grow successfully. Our native clay soil does not drain well so it must be amended for camellias. Our alkaline soil needs to be acidified, and sulfur pellets are one way to achieve this. The plants need some shade and need to be kept moist. Mulch helps hold in moisture, and pine needles, redwood bark, and coffee grounds are all good organic materials that will break down over time and help improve the soil. Pick up flowers as soon as they fall to the ground to avoid the spreading of a disease called Camellia petal blight.

More information: Camellia Pests

Months applicable: January, February, March, April, May, September, October, November, December

Tags: Ornamental Plants, Trees & Shrubs

Carpenter Bees

Female carpenter bees are large, black and shiny. Male carpenter bees are similar in appearance to bumble bees. Both are about an inch long. Males do not sting and females sting only rarely. Carpenter bees are considered beneficial insects because they pollinate many plants and trees. For their nests, they tunnel into unpainted softwoods such as pine, fir and redwood in house or garden structures. Adults over winter in the nests, emerge in the spring, mate, deposit food in the tunnels and lay eggs. The tunnels are sealed with wood pulp and the new adults chew their way out. After the bees emerge, fill the holes with steel wool and wood filler. Apply paint to the surface to prevent re-entry. Further information is available in the UC Pest Note on Carpenter Bees.

Months applicable: May, June

Tags: Beneficial Insects

Carrot Culture

If you have a light fluffy soil, perhaps in a raised bed, you can grow those long beautiful carrots you see in the grocery store. However most of us have a heavy clay soil and it is best to grow the shorter varieties. Adding organic material such as compost rather than manure is good. The seeds are very tiny and mixing sand with them will help you not over-seed. Plant no more than 1/2 inch deep. Carrots are slow to germinate and could take as long as 3 weeks. Keep the soil moist until they're up. Thin to 2 or 3 inches apart. Plant every few weeks for a continuous crop. If you have limited space, try growing in among your ornamentals, their feathery tops can look quite pretty. They can also be grown in a container. Some common problems are twisted roots from planting too close together, forked or deformed roots from clods and rocks in the soil, hairy root from too much nitrogen and splitting from too much water.

Months applicable: February, March, April, September

Tags: Techniques, Vegetables

Certified Arborists

Months applicable: January, February, March, December

Tags: Best Practices, Garden Basics, Trees & Shrubs

Change to Cool Season Planting

Months applicable: September, October

Tags: Techniques, Vegetables

Chayote

Months applicable: February, March, April

Tags: Vegetables

Chill Hours

Months applicable: January, February, December

Tags: Fruits & Nuts

Chill Hours for Fruit Tree Selection

When selecting a fruit tree to plant, make sure that the varieties you choose will do well in our changing climate. Deciduous fruit trees like plums, peaches, and apples require a winter dormancy period that is measured in chill hours. In our warming climate, some traditionally grown varieties such as Bing cherries may not receive enough chill hours to fruit well. Where you live and the microclimates in your yard will affect your choices. See Chill Hours for more details on how chill hours are calculated and what low chill hour varieties are available.

Months applicable: Any month

Tags: Fruits & Nuts

Chrysanthemums

Months applicable: April, May, June, July

Tags: Best Practices, Ornamental Plants

Citrus Bud Mite - Leave It Alone

Have you ever seen weirdly shaped lemons or oranges that appear to have 'fingers'? This condition is caused by the Citrus Bud Mite.

It attacks newly forming flowers and fruits. The mite is only visible with a magnifying glass and has a elongated yellow body with four legs that appear to come out of its head. The mites feed inside the buds, killing them or causing a rosette-like growth of the subsequent foliage and distortion of flowers and fruit. The problem is usually limited to just a few fruit on the tree.

Previously recommended oil sprays have not been proved effective. This is one of those pests that is best left alone. The oddly-shaped fruit is edible.

For more information see UC Pest Note on Citrus Bud Mite.

Months applicable: November

Tags: Fruits & Nuts, IPM, Invertebrates, Vertebrates

Citrus Fertilizing

In California, most soils contain adequate nutrients for citrus growth, except nitrogen. Nitrogen is the primary nutrient required by the trees, and there are commercial fertilizers balanced specifically for citrus. One-year-old trees will need 1/10 of a pound of nitrogen, while mature trees need approximately 1-1/2 pounds. These amounts should be divided into two to three applications.

Blood meal without all the fillers is an excellent source of nitrogen, or you can purchase a balanced product that contains zinc. Spread the fertilizer evenly over the entire root area and water in.

For more information, refer to the UC Pest Note on Fertilizing Citrus, and Questions and Answers to Citrus Management from the UC Davis Home Orchard website.

Months applicable: January, February, May, June

Tags: Fruits & Nuts

Citrus Leaf Drop

Leaf drop from citrus trees is normal. Washington Navel oranges may lose over 3,000 leaves a day during peak leaf drop in the spring. Valencia oranges may lose about 1500 a day. Problems that can cause excessive leaf drop beyond these numbers are lack of water and a heavy infestation of spider mites. The tree's leaves will have brown spots if affected by the mites. You can wash them off with a strong water spray. Bud and small fruit drop is also normal. For further information see UC Pest Note on Diseases and Disorders of Citrus Leaves and Twigs.

Months applicable: March, April

Tags: Abiotic Disorders, Fruits & Nuts, IPM, Invertebrates, Vertebrates

Citrus Leafminer

What causes young, healthy citrus leaves to become gnarled and disfigured and what can be done about it? This damage is due to the citrus leafminer moth that lays eggs on new citrus leaves. Its larvae burrow into the leaf and leave tunnels as they feed, visible as meandering serpentine mines. Our advice: don’t worry about it. Leafminers can slow the growth of young trees but even heavily damaged trees are unlikely to die. Leafminers only attack young leaves — the tough leaves of mature plants resist infestation and fruit is not affected. Damaged leaves still produce food for the tree, so don’t cut them off. If you do, it will stimulate the tree to produce more new leaves — which will attract more leafminers!

More information: Citrus Leafminer

Months applicable: January, February, March, April, May, September, October, November, December

Tags: Fruits & Nuts, Invertebrates

Citrus Pruning and Care

Once the threat of frost is past (typically March 15), it's a good time to cut back branches that touch the ground, fences, or other structures. Thin the tree to let more air into the middle. Trim out crossing branches and anything that looks dead.

Pruning is not needed for fruit productivity yet may be desired for size management. Pruning will also help control scale and aphid infestations. If you see ants in the tree, use a sticky goo (such as Tanglefoot) on the trunk to keep them out of the tree. Be sure to apply the goo on top of tape rather than directly on the trunk. The ants 'protect' the scale and aphids. If you see scale (bumps on bark), thoroughly spray with horticultural oil to suffocate them.

Yellowing of leaves is normal this time of year as the iron that keeps the leaves green is chemically unavailable because the soil is too cold. When the soil warms up (over 60° F), check for yellowing. You may not need to apply a nitrogen fertilizer if the new leaves are green.

Refer to the UC Home Orchard web site for more Citrus Care information.

Months applicable: March

Tags: Best Practices, Disease, Fruits & Nuts, Invertebrates, Vertebrates

Citrus Sooty Leaves

Sooty mold on citrus may be a byproduct of sucking insects such as aphid, mealy bug, soft scale or whitefly. Ants will protect these pests against predators in exchange for the honeydew that the pests produce. The sooty mold grows on the honeydew. Try washing off the sucking insects with a strong water stream. The next step is control of the ants. Ants may be managed by applying a sticky compound around the trunk and trimming limbs touching buildings or other access points. Baits at the base of the tree also help. For more information about specific controls, see the UC Pest Note on Sooty Mold.

Months applicable: April

Tags: Disease, Fruits & Nuts, IPM, Invertebrates, Techniques

Clean Garden Beds

In preparation for winter, remove dead plants, leaves, fruit (mummies), and flowers from garden beds. Many insects and diseases overwinter in fallen debris. Do not compost any plant materials you think might be diseased.

As part of the clean up, take a moment to examine their roots and stems. Do the roots show signs of root knot nematodes? Do the stems show signs of Verticillium or Fusarium discoloration? If your plants suffered from any soilborne pathogens this year, consider strategies for managing it next summer. If you have the space, you could plant in a different spot next year. If you can’t rotate locations, try choosing varieties that are marked as being resistant. You could even grow in containers for a season.

Months applicable: December

Tags: Best Practices, Disease, Garden Basics, Soil

Clean Up Fallen Fruit

Pick up fallen fruit daily to prevent attracting critters or diseases. If your fruit is being eaten at night then rats are the likely culprit, if it's during the day it may be squirrels. Holes, rather than bites, are made by birds. In addition to harvesting regularly, ripening fruit can be protected with a netting fine enough to exclude birds and small animals

Months applicable: July, August

Tags: Fruits & Nuts, IPM, Vertebrates

Codling Moth

If you grow apple or pear trees, you may have noticed small holes in the maturing fruit and then discovered a worm inside. "Worms" in your apples are actually the larval form of the codling moth. Codling moth larvae can cause a great deal of damage to apples, pears, plums, and walnuts by penetrating the fruit and boring into the core.

Trees should be monitored every week for signs of infestation. Infested fruit should be removed and discarded to break the codling moth life cycle. Sanitation is an important non-chemical step in controlling this pest. Make sure to pick up fallen fruit promptly, and pick apples with holes that are still on the tree. This will keep future populations down.

Pheromone traps can be hung in isolated trees. But if you have just one apple tree don't bother. You will just attract codling moths to your tree.

Fruit can be bagged for protection, but this method is very labor-intensive. Heavy infestations may require the use of pesticides, but proper timing of sprays is critical. Read the UC Codling Moth Pest Note for more information.

Months applicable: May, June, July, August

Tags: Best Practices, Fruits & Nuts, IPM, Invertebrates

Composting

Composting is a good way to repurpose yard and kitchen waste, and it provides a free method to feed plants and improve soil structure. If you are unsure about how to begin composting, take a look at this simple how-to compost page. You can also go to the UCCE Composting Education Program website to learn more about free two-hour classes offered throughout the county.

As the weather warms up, compost piles dry out faster. Keep compost piles as damp as a wrung-out sponge to keep organisms alive and working on decomposing yard waste. Turning the pile to incorporate more oxygen also supports life in the compost pile.

Months applicable: June, July, August, Any month

Tags: Best Practices

Consider Dehydrating Some Of Your Harvest

If you have more fruit than you know what to do with, dehydration can be an excellent way to preserve it. Apricots, apples, pears, figs, and tomatoes are all great candidates for drying. While making jams, jellies, cobblers, and pies is one way to use up an abundant harvest, they add fat and sugar to our diet, dried fruit can be a healthy alternative! Onions and garlic can also be dehydrated to last indefinitely.

Also see the publication on Dehydrating Basics by the UCCE Master Food Preservers of Amador/Calaveras Counties.

Months applicable: August, September

Tags: Fruits & Nuts, Techniques, Vegetables

Container Color Choice

If you are growing plants in containers, keep in mind that light colors do a better job at reflecting the sun. This helps keep the soil from drying out too quickly and reduces the chances of the roots burning. If you already have dark pots, consider painting them a lighter color, or be especially careful about watering.

Months applicable: April, May, June, July

Tags: Best Practices, Container Gardening, Waterwise Tips

Control Insect Pests with Horticultural Oil

Spray apple, pear, peach and nectarine, apricot trees with horticultural oil during the dormant period to control scale, and aphid and mite eggs. For more information on using horticultural oil to control pests consult:
- UC Pest Note on Scales
- UC Pest Note on Aphids
- UC Pest Note on Spider Mites

Months applicable: January

Tags: Fruits & Nuts, IPM, Invertebrates

Controlling Bermudagrass

Bermudagrass is a warm season grass, going dormant in winter, so that's not the best time of year to fight it. Spraying it in winter won't work because it can't take up the poison since it is not actively growing. But you can install sheet mulching to smother spring/summer growth, or dig out roots if the soil is not too wet. For more information, read the UC Pest Note on Bermudagrass.

Months applicable: January

Tags: IPM, Lawns, Techniques, Weeds

Cool Season Vegetables

Cool season vegetables include many greens (spinach, arugula, cabbage, collards), root vegetables (carrots, beets, radishes, turnips), and cole crops (broccoli, cabbage, cauliflower, kohlrabi). Cilantro and peas also do well in the fall when it is a little cooler.

If starting from seed, August is the time to start seedlings for fall vegetables. Broccoli, cauliflower, beets, and fennel will take about 6 weeks to grow to transplant size. Greens such as lettuce, spinach, arugula, chard, and kale will be ready in 4 weeks. So for planting in mid-to-late September, aim to start them in early to mid-August. You can direct seed them on the ground if you have the space. The soil should still be warm enough for seeds to germinate but shade them from the hottest afternoon sun, and keep the seeds moist.

If buying transplants from a nursery, you can wait until September. In Santa Clara County, many of the cool season crops that are planted in September or October can be planted again in February and March. You can get in another crop before it's time to put summer vegetables in the ground.

A big advantage of cool season vegetables is that they need less supplemental water due to lower temperatures, fewer daylight hours, and rain. There are also fewer pest problems in the winter. Cool season vegetables grow well in temperatures ranging from 55°F to 75°F, at locations with 6–8 hours daily of sun.

Months applicable: August, September, October

Tags: Best Practices, Techniques, Vegetables

Cottony Cushion Scale

Scale insects populate the stems or branches of plants and suck out the nutrients. Some are soft and some are armored during part of the life cycle. Cottony cushion scale is a soft variety that is often seen on apple trees. The crawlers are reddish and the females develop elongated white egg sacs on their backs, but it is most likely the molting skins that look like cotton that will alert you to their presence. Small infestations can sometimes be wiped off with gloved fingers. Natural predators may also move in to take care of the problem. There are beetles and parasitic flies that can provide good control. Keeping ants out of the tree will also help because ants will protect the pests in order to be able to eat their sugary exudate.

More information: Cottony Cushion Scale Pest Note

Months applicable: June, July, August

Tags: Fruits & Nuts, IPM, Invertebrates, Trees & Shrubs

Cover Crops

You may want to rest in the winter, but the soil life needs to remain active and protected and preferably weed-free. If you’re not planting vegetables or ornamentals in an area for a few months, try plants designed to feed the soil and the organisms that live in it. Cover crops are ideal for putting nutrients back into your soil and keeping weed growth to a minimum. Fava beans are the most popular cover crop in this area and can be seen in abundance in community gardens. Other common crops are clover, vetch, and bell beans. Different cover crops provide a variety of benefits. Cereals such as oats and barley to help build organic matter. Beans and other members of the legume family fix nitrogen from the air and make it available in the soil and to plants. The roots also break up heavy clay soil and improve its structure. While fava beans are edible, they provide the most nitrogen to the soil if they are cut up and dug in while they are still in the flowering stage.

More Information

• Choosing and Using Cover Crops
• Cover Cropping in Home Vegetable Gardens

Months applicable: September, October

Tags: Soil

Creating a Pollinator Garden

Pollination is the process of transferring pollen from the anthers of a flower to the stigma. It is a requirement for the production of fruits and seeds. In addition to wind and water, pollinators include bees, hummingbirds, butterflies, moths, bats, flies, and beetles.

You can support the pollination process—and help counter habitat destruction—by selecting plants attractive to common pollinators. UC has many resources for planning a pollinator garden. Here are a few to get you started!

• How to Attract and Maintain Pollinators in Your Garden, UC ANR Publication 8498
• Creating a Pollinator Garden, UC Master Gardener Program Statewide Blog
• Encouraging Native Bees & Other Pollinators, California Garden Web
• Nesting and Overwintering Habitat, Xerces Society Publication

Months applicable: Any month

Tags: Beneficial Insects, Herbs, Ornamental Plants

Deadheading

Deadheading means removing spent blossoms from your plants. Not all plants need deadheading, but if the flowers stay on the plant and become unattractive (think roses, dahlias, marigolds, coneflowers, geraniums and many more), then consider a little pruning. The technique varies by plant; some spent flowers can be snapped off by hand (dahlias), others are better done with hand pruners (roses), and some can be sheared off all together (lavender). You'll not only make the plant look better, you'll stimulate additional blooming for plants that have a long blooming season.

Months applicable: May, June, July, August, September

Tags: Best Practices, Garden Basics, Ornamental Plants, Techniques

Decay in Trees

Shelf-like fungus or mushrooms growing on trees indicates advanced internal decay. Once these external fruiting structures appear, the infection is likely widespread inside the tree. To reduce the chance of infection, protect trees from injury, provide adequate water and fertilization, and prune trees correctly when young to avoid significant pruning cuts when they’re older. Regularly inspect trees and consult an arborist if you spot fungal growths or other signs of decay. The arborist can assess the extent of rot and the structural integrity and make recommendations. More information: Wood Decay Fungi in Landscape Trees

Months applicable: Any month

Tags: Fruits & Nuts, Ornamental Plants, Trees & Shrubs

Deer

Although there's no such thing as a deer-proof plant, some can be called deer-resistant. Plants with strong smells, woolly or hairy leaves, or prickly or thorny parts are less appetizing to deer. Other strategies include deer repellents, enclosing plants in wire cages, netting, or tall fences. Read more in the UC Pest Note on Deer and use our search for Deer Resistant Plants.

Months applicable: August

Tags: IPM, Vertebrates

Direct Seeding

Months applicable: May, June

Tags: Techniques, Vegetables

Don't Move Firewood

Tree-killing insects and diseases can lurk in or on firewood. These insects and diseases can’t move far on their own, but when people move firewood, these pests can jump hundreds of miles. Beetles that have done significant damage in Southern California are the Goldspotted Oak Borer and Invasive Shot Hole Borers. Let’s keep them out of Santa Clara County.

Months applicable: January, December

Tags: Best Practices, Disease, IPM, Invertebrates

Don't Plant an Invasive Plant

According to PlantRight, so-called invasive plants "escape into open landscapes and cause a variety of ecological problems. They displace native plants and wildlife, increase wildfire and flood danger, clog valuable waterways, degrade recreational opportunities, and destroy productive range and timberlands."

PlantRight has identified the following as invasive in Northern California: Green fountain grass (Pennisetum setaceum), Periwinkle (Vinca major), Pampas grass (Cortaderia selloana), Highway iceplant (Carpobrotus edulis), Mexican feathergrass (Stipa / Nassella tenuissima), Yellow Flag Iris (Iris pseudacrorus), Water Hyacinth (Eichhornia crassipes).

Months applicable: April, May, June, July, August, September

Tags: Ornamental Plants

Dormant Oil Spraying

Deciduous fruit trees lose their leaves seasonally, usually in the autumn. They enter a period of dormancy when they are not actively growing and there is little activity within the plant. This is the time to apply dormant oil sprays to smother soft-bodied insects such as scale, aphids, and mites. First, do any needed pruning so that you will not be spraying branches that will soon be removed. Then inspect for pests that are overwintering on the trees, or remember pest and disease problems you noticed during the growing season. Although dormant oils may count as organic, it is still best to use them only if pest problems have been observed.

Months applicable: January, February, March

Tags: Best Practices, Fruits & Nuts, IPM, Invertebrates

Dormant Rose Pruning

Winter is the best time to prune roses even if they haven’t gone completely dormant. The old advice was to cut the canes down drastically, but that isn’t necessary for our climate. Instead, just cut back about one-third to one-half of the total height. In other words, take a 4-foot bush down to about 2–3 feet. When cutting back a cane, make the cut at an angle just above an outward pointing bud. Take out any dead or diseased canes, remove suckers below the graft union, and branches that are crossing or growing towards the middle of the plant to improve airflow. Clean up old leaves on the plant and ground to reduce rust and black spot.

More Information: Rose Care

Months applicable: January, February, December

Tags: Ornamental Plants, Techniques, Trees & Shrubs

Dormant Season Berry Pruning

The time of year to cut back raspberry canes depends on the type of raspberry you’re growing. For summer-bearing varieties, remove all the floricanes that bore fruit immediately after the summer harvest, leaving the new green primocanes. Then, in the winter, you can just inspect and remove any weak or damaged canes. For fall-bearing (also called everbearing) varieties, you have a choice. Canes that bore fruit in the fall will produce a small crop in the summer, then can be cut down. Or, to skip the summer crop in favor of a heavier fall crop, you can cut down all growth in the winter to encourage vigorous summer growth.

More Information: Blackberries and Raspberries

Months applicable: January

Tags: Fruits & Nuts

Drip Irrigation

Consider various forms of irrigation conversion! Irrigation systems, especially drip and micro-sprinklers, have drastically improved over the last few years. For example, there are kits that convert pop-up sprinkler heads to low-flow systems. The conversion kits include a pressure regulator to control changes in pressure and a filter to improve water quality. Water usage is reduced through better water management, control of distribution and less loss from evaporation. Other advantages include :

- Water is placed more accurately and efficiently in the root zone, it is applied at a slow rate that reduces loss from runoff.
- Dry soil between plants allows you to work in the garden between irrigating.

The key to success is watering long enough to supply adequate water to the root zone. Inappropriate watering commonly damages landscape plants. As with any irrigation system, they are efficient only when soil around the plants being irrigated is regularly monitored for proper moisture levels (Reference: UC Pest Note Poor Water Management, Poor Drainage).

Months applicable: April, May, June, July, August, September, Any month

Tags: Best Practices, Irrigation, Techniques, Waterwise Tips

Drought Tip - Irrigate Efficiently

Water restrictions are being put into place all over the state due to the current drought. With over half of urban water used in landscapes, it is essential to make sure your irrigation system is efficient. Watch your plants for signs of underwatering, overwatering, or uneven watering. Consider reducing irrigation times. And make sure your water bill hasn’t unexpectedly jumped. Also, adjust systems on timers monthly as the weather changes or use an automatically-adjusting smart controller. A smart controller can make the needed adjustments after initial programming with plant, location, and other relevant information. Our Santa Clara County clay soil absorbs water slowly, so only water for a few minutes at a time to avoid runoff. Then repeat until the water penetrates to the depth of the roots. Inspect drip and sprinkler systems regularly to make sure there are no leaks, emitters are not clogged and it is watering the plants and not the sidewalk, also make sure the water is going to the root zones of the plants. If you run a hose to a plant, set a kitchen or cell phone timer so you don’t forget that the water is running. Valley Water can help residents with Water Wise Outdoor Surveys and Landscape Rebate Programs.

More information: Irrigation System Audit

Months applicable: March, April, May, June, July, August, September, Any month

Tags: Best Practices, Irrigation

Drought Tip - Laundry to Landscape Irrigation

A laundry to landscape system is an easy way to save water in times of drought. It can be installed easily at a low cost to send rinse water from clothes washers directly to the landscape.

Suitable plants include fruit and ornamental trees, shrubs, and ornamental annuals. It’s not applicable where the water would come in direct contact with fruits or vegetables.

More information: Laundry-to-Landscape Graywater System

Months applicable: March, April, May, June, July, August, September, Any month

Tags: Irrigation, Waterwise Tips

Drought Tip - Lawns

This landscaping feature—imported long ago from rainy, foggy England—does not translate well to a semi-desert with frequent droughts. Lawns demand a huge investment of water, money, time, work, equipment, and fertilizers and other chemicals. According to Scientific American, U.S. lawns require the equivalent of 200 gallons of drinking water per person per day. Many people are joining the "lose the lawn" movement, and UC Davis offers several plans and examples to help you get started on a yard design more appropriate for our climate. Valley Water offers rebates and guidance for lawn replacement. If your family uses your lawn and you want to maintain it this summer, follow the irrigation regulations of your local water company and aim for survival rather than a lush green carpet. A lawn that looks light green or brown will often be dormant (not dead) and will perk up with the winter rains; the roots can survive much longer than the blades above ground. Keep it mowed in the meantime so that weeds don’t go to seed and take over. Concrete and synthetic (plastic) turf do not benefit the environment other than not using much water.

More information: Drought Resources

Months applicable: March, April, May, June, July, August, September, Any month

Tags: Lawns, Waterwise Tips

Drought Tip - No Fertilizer

Fertilizing your lawn and landscape encourages lush new growth. That’s usually what we want, but not during a drought. That new growth requires extra water to support it. Plus, if a plant is already drought-stressed, fertilizer may cause it more stress by stimulating growth that can’t be supported with limited water. In other cases, plants may slow or shut down growth under drought stress to conserve resources and will not use fertilizer.

More information: Skip fertilizing

Months applicable: May, June, July, August

Tags: Lawns, Ornamental Plants, Trees & Shrubs, Vegetables, Waterwise Tips

Drought Tip - Trees Come First during Drought

Months applicable: July, August, September

Tags: Best Practices, Fruits & Nuts, Irrigation, Trees & Shrubs, Waterwise Tips

Drought Tips - Vegetable Gardening

• Plant only as much as you can use. Produce that isn’t harvested wastes water.
• Plant in groups or triangular patterns rather than straight rows. This lets you water more efficiently, and the plants form a leafy canopy that shades the soil.
• Mulch, mulch, mulch to decrease moisture loss and reduce competition from weeds.

For more information: Ten Tips for Vegetable Gardening during a Drought

Months applicable: May, June, July, August

Tags: Best Practices, Techniques, Vegetables

Drought or Disease

It can be hard to tell if a stressed plant is suffering from a disease or a lack of water due to drought. Water stress causes plants to lose their leaves, shrivel and droop, with split bark and brown branch tips soon to follow. These symptoms could be mistaken for diseases that attack the plant’s roots and vascular system. But it’s also true that water-stressed plants can be more susceptible to pathogens due to their weakened state. Check soil moisture for your ailing plant, and if it’s dry, try irrigating the plant. If it doesn’t respond, contact the our Help Desk for further assistance.

More Information: Drought or Disease

Months applicable: Any month

Tags: Disease, Fruits & Nuts, Techniques, Trees & Shrubs, Waterwise Tips

Earwigs

Earwigs are third only to snails and slugs in causing plant damage. While they are beneficial because they eat insects such as aphids, they also feed on soft plants. Earwigs can do quite a lot of damage if there is a high population. They feed at night and hide in moist, tight-fitting places during the day. Trap them by putting out moistened, tightly rolled newspaper or corrugated cardboard in the evening. In the morning dispose of the paper and the trapped insects. Other control methods are described in the UC Pest Note on Earwigs.

Months applicable: May, June

Tags: Beneficial Insects, IPM, Invertebrates

Easter Lilies

Months applicable: April

Tags: Ornamental Plants

Echeveria

It's easy to have color in your yard without using a lot of water. Instead of planting thirsty annuals, consider some of the many types of succulents. Echeveria does well in containers or in the ground. Plant them in well-drained soil and allow the soil to dry between waterings. They aren't particular about sun or shade, although some can be a little sensitive to full afternoon summer sun.

Months applicable: Any month

Tags: Ornamental Plants, Waterwise Plants, Waterwise Tips

Eliminating Perennial Weeds

To control perennial weeds, repeatedly cultivate soil in summer and, when possible, keep the soil completely dry for several months to dehydrate weed stems, rhizomes, or tubers.

Months applicable: June, July, August

Tags: Best Practices, Weeds

Empty Standing Water

Make sure you don’t have any water sitting around from our late rains. Mosquitos breed in standing water and can pass along deadly West Nile Virus to people. Check and dump water from any buckets, pots, saucers, dishes, or wheelbarrows. Put containers away or turn them over to avoid collecting additional water. Keep chemicals balanced in swimming pools. Ponds, fountains, and bird baths can also be breeding grounds. Add mosquitofish to these bodies of water to eat mosquito larvae. They are an environmentally friendly means of control and are available free of charge from Santa Clara County Vector Control.

More information: Empty Standing Water Video

Months applicable: March, April, May

Tags: Best Practices

Encouraging Dahlia Blooms

Months applicable: June, July, August

Tags: Garden Basics, Ornamental Plants, Techniques

Eugenia Psyllid

This psyllid has been a real problem in California. New leaves on the infected Eugenia look very much like peach leaf curl. The leaves also may become discolored. Thanks to the diligent work of the entomology researchers in biological insect control at UC Berkeley, a parasitic wasp called Tamarixia was released in Santa Clara County in 1993. The wasp is known to go as far as 45 miles and is found throughout the county. It is essential that no insecticide be used on Eugenia species. The Tamarixia wasp cannot do its job if it's poisoned. For more information see the UC Pest Note on Psyllids.

Months applicable: May, June

Tags: Disease, Fruits & Nuts, IPM

Extending the life of cut flowers

Use lemon-lime soda or lemon juice to extend the life of cut flowers. The following mixtures supply food for the flowers and enough acidity to deter microbial activity.

• Lemon-lime soda mixture. Mix 1 part regular lemon-lime soda (not diet soda) with
  3 parts warm water. Add 1?4 teaspoon of household bleach per quart of this solution.
• Lemon juice mixture. Mix 2 tablespoons of lemon juice (fresh or bottled), 1 tablespoon of sugar, and 1?4 teaspoon of bleach per quart of warm water.

For more information, refer to Extending the Freshness of Cut Flowers at Home.

Months applicable: Any month

Tags: Best Practices, Ornamental Plants, Techniques

Fall Garden Cleanup

It’s an excellent idea to keep the garden clean at all times and to remove dead or dying plants or diseased material. Yet there may be bigger seasonal cleanups when taking out plants that have finished producing or that need to be removed to make room for new plants. Trim woody or overgrown perennials. Remove plant debris that allows insects and diseases to overwinter and then reproduce. Always pick up fruit promptly from the ground to not invite critters or allow diseases to proliferate. It's best to leave fallen leaves in place unless they are diseased. They provide a mulch layer while slowly breaking down and returning nutrients to the soil and then back to the plants. Particularly during a drought, having the soil covered is important for moisture retention. If the leaves are diseased, they need to be removed and put out with the yard waste. Monitor the health of your plants while you're out cleaning up.

Months applicable: October, November

Tags: Best Practices, Disease, Fruits & Nuts, Ornamental Plants, Techniques, Trees & Shrubs, Vegetables

Fall Irrigation

You can still expect some warm weather during October, so keep watering the garden until the fall and winter rains begin. As temperatures drop, less water is needed for plants.

Check your soil periodically by digging gently into the soil next to the root, about 6 inches down (deeper for bigger plants). If the soil does not hold a shape when squeezed it is too dry; if it continues to hold shape after the pressure is released it is too wet; if the soil has a shape then crumbles quickly, it has the right amount of water.

Hydrozone any new plantings by putting plants with similar water needs together. This helps ensure that less water is wasted and that all plants get the right amount of water.

If you have an automatic watering system, this is a good time to inspect the system for leaks and blockages, check the timer for batteries, and reprogram the system as necessary for cooler weather and rain.

If you don't have an automatic watering system, think about installing one. Many systems are very affordable and easy to install by the home gardener. Take a look at some "smart meters". They are more expensive, but incorporate weather conditions, your location, and your soil into the programming, making them very efficient.

Months applicable: October

Tags: Best Practices, Irrigation, Techniques, Waterwise Tips

Fertilizing Fruit Trees

As fruit starts to develop, trees and vines use nutrients to help with this energy-intensive task. This is a good time to plan a strategy for fertilizing your trees.

In the first year, a very light application of nitrogen (N) is desirable for most soils. Do not make first year applications before six to eight inches of new growth occurs. Split applications are safest, one or two months apart, so one application might be made this month.

After the first year: research indicates that summer fertilizer applications (August to mid-September) are more efficient than late winter (traditional) applications.

Fully mature fruit trees may not need fertilizing. Read more at UC Home Orchard Fertilization page.

Months applicable: February, August

Tags: Best Practices, Fruits & Nuts

Fertilizing Ornamentals During Drought

One way to manage plants during drought is to reduce the amount of fertilizer used. While plants need nutrients to survive and be healthy, excess fertilizer promotes additional growth, which then demands more water.

Months applicable: May, June, July, August

Tags: Ornamental Plants, Waterwise Tips

Fire Blight

This disease is so named because brown or black leaves, fruit, and branches look as if they have been burned. It is most common on apple and pear trees. Late spring and early summer are the time fire blight shows itself.

It is spread by insects, rain, or pruning. The bacteria enter through the blossoms and travel down the tree. If left unchecked, fire blight can enter the trunk and kill the entire tree. Prune infected branches back to healthy wood, at least eight inches below visible damage. If the inside of the branch is discolored, you need to cut back still further. Clean pruning tools between cuts so as not to spread the infection. A less effective way to control fire blight is to spray the open blossoms with a copper spray. Planting varieties that are less prone to fire blight is helpful. Always promptly clean up fallen fruit and leaves.

For more information, see the UC Pest Note on Fire Blight.

Months applicable: April, May, June

Tags: Disease, IPM, Techniques, Trees & Shrubs

Firescaping

Months applicable: July, August

Tags: Best Practices, Ornamental Plants, Trees & Shrubs

Flowering Vines

Vines are plants that climb or sprawl and can easily outgrow their spaces if not pruned annually or more often. Many are pruned in the winter when they are dormant. This reduces shock to the plant and allows you to better see the structure when pruning. If the vines are flowering, wait until after the blooms have finished. Some vines get cut back almost to the ground to renew them. Some are cut back to the beginning of the herbaceous growth, leaving the woody vines. Others are pruned simply for shape or size. The UC Davis Arboretum All-Stars brochure includes several flowering vines. All-Stars are plants that have been tested and proven to thrive in California. The brochure lists pruning needs. It also has photos, characteristics, and requirements of the plants if you are looking for new plants.

Months applicable: January, February, March

Tags: Best Practices, Garden Basics, Ornamental Plants, Techniques

Flowers To Attract Beneficial Insects

Certain flowers help attract natural enemies of pest insects in the garden. Tiny wasps that parasitize certain insect pests or their eggs need pollen and nectar to survive. Predatory insects (syrphid fly larvae, lady beetles, lace wings, and many others) and mites survive on pollen and nectar from flowers when pest populations are low, and some feed on pollen in order to reproduce.

Most of these beneficial insects are small, and so the best flowering plants to include in the garden are those that have small flowers that have pollen and nectar easily accessible and that bloom throughout the season. Avoid flowers that are difficult to weed out when they reseed.

Many flowers that attract beneficial insects are easy to start from seed and this month is a good time to start them – some indoors any time or outdoors later in the month after frost danger has passed. Examples include sunflowers (try dwarf varieties like ‘Sunspot’ for smaller spaces), calendula, cosmos and many herbs like dill, basil and borage.

Other flowers and herbs that attract beneficial insects are easier to buy as plants. A few examples that can be planted this month are coreopsis, asters, and thyme.

Reference info:
UC Pest Note on Biological Control and Natural Enemies of Invertebrates
UCCE notes on Attracting Beneficial Insects to Your Garden.

Months applicable: March

Tags: Beneficial Insects, Herbs, Ornamental Plants

Forcing Bulbs

Forcing bulbs involves getting spring bulbs to bloom indoors during winter. Start by selecting the bulbs. Some bulbs such as hyacinths need to be chilled, while others like paperwhites do not. Select a container without holes and place a layer of rocks on the bottom. Position the bulbs on the rock layer, pointed end up; then fill with water to the bottom of the bulbs. Top up water if the level drops. Replace water if it gets murky. Keep the container in a cool dark location until the roots start growing; then move it to a sunny location and enjoy the display.

More information: Forcing Bulbs Indoors

Months applicable: November, December

Tags: Ornamental Plants

Free the Trees

As your young trees grow bigger and stronger, remove supporting stakes or loosen the straps as early as possible. Some movement of the tree is important to make it healthier in the long run. If the tree is able to stand on its own, it will develop a thicker trunk with a taper at the bottom.

Months applicable: September, Any month

Tags: Abiotic Disorders, Best Practices, Fruits & Nuts, Techniques, Trees & Shrubs

Fresh Cut Flowers from Your Garden

We have a webpage to help you choose and grow beautiful cut flowers for your home or to give away. The Cut Flower Planting Chart lists ornamentals we’ve grown successfully. We selected these for their hardiness, appeal to pollinators, and production of good cutting flowers. The chart tells you when to start these flowers from seeds or when to transplant, plus when you can expect to see blossoms.

More information: Tips on planting a cut flower garden

Months applicable: January, February, March, April, May, June, Any month

Tags: Garden Basics, Ornamental Plants

Fresh Fruits and Vegetables Without a Garden!

If you like the freshest possible produce but don't have the space or time to grow your own, find a certified Farmers Market selling directly to consumers. The County of Santa Clara website has a Farmers Market page with links to certified Farmers Markets.

Months applicable: June, July, August, September

Tags: Best Practices

Frost Dates

The approximate first and last frost dates for Santa Clara County, depending on your location, are November 15 and March 15. These are important dates for gardeners to remember.

First frost date—this is the earliest date you should expect frost to occur. If you have plants that need to be brought in for the winter, or crops you need to pick before frost, this date will be important to you.

Last frost date—after this date, you wouldn't expect any more frosts. It's generally used as a milestone when pruning frost-sensitive plants (such as citrus where you don't want to stimulate delicate new growth until the danger of frost is past).

For our climate, the last frost date is not a reliable metric for when to transplant summer vegetables. Daytime temperatures and soil temperatures are more important. See entries for individual vegetables for specific recommendations.

Also see: Frost—Avoidance and Dealing with Damage

Months applicable: January, February, March, November, December

Tags: Garden Basics

Fruit Damage

If your fruits are ready to pick and you don't get to them first, there are critters that will let you know when they are ripe. For example, for citrus, snails leave little holes in the outside peel, rats hollow out the fruit and squirrels carry them off, often leaving partly eaten fruit on a nearby fence.

To determine what’s eating your fruit - start by narrowing down the list of possible pests in your area. Check the damage to determine whether it is likely caused by insects, birds, or rodents. Determine what time of day the damage happens. Squirrels are active during the daytime, and rats are mainly active at night. Look for other signs, such as placement of the damaged fruits, tracks, and possibly droppings, and compare that to the habits of the pest you suspect. When you are sure what the pest is, you can take appropriate action to protect your fruits.

Resources:

• Identify citrus damage from insects and other pests
• Who is eating my tomatoes

Months applicable: February, July, Any month

Tags: Best Practices, Fruits & Nuts, IPM

Fruit Thinning

Months applicable: April, May, June

Tags: Best Practices, Fruits & Nuts

Fruit Tree Dormant Care

In winter, as your deciduous fruit tree goes dormant, you can do a few things to ensure a healthy and productive growing season next year. Thin or cut back branches to improve airflow and sunlight penetration. For pest and disease control, remove dead or damaged branches and mummified fruits from the tree. Dispose of diseased wood, fruit, and leaves from the ground.

If you've had major pest infestations on your fruit trees this year, now is a good time to use dormant oil sprays. These are used to reduce overwintering populations of insects. They work by smothering soft-bodied insects and eggs when applied at the proper times in the life cycles of the pests. Identify the issue you had this year, and choose the appropriate spray. Make sure to follow the instructions carefully as you apply it. See Winter Pest Management and Fruit Tree and Vine Care Calendar for more information.

Months applicable: December

Tags: Fruits & Nuts

Fruit Tree Grafting

When pruning dormant fruit trees, you may want to save cuttings (scions) for later grafting onto other fruit trees. Grafting is a technique that allows you to have multiple varieties of compatible fruit on one tree and is a great space saver. It works by joining the vascular tissues of a shoot (scion) from one tree to a different tree that provides the root system. If the graft is successful, the scion will continue to grow and maintain the characteristics and fruit of the scion plant. Fruit trees can have new varieties grafted to them when they are dormant in January and February.

Scions are available in January or February at the California Rare Fruit Growers (CRFG scion exchange). Their January event also includes training classes. Check the CRFG - Santa Clara blog for the date.

More information on grafting can be found at:

• Grafting and Budding on the UC Home Orchard website
• Grafting Dormant Deciduous Fruit Scions at the California Rare Fruit Growers website
• Budding and Grafting Demystified presentation slides from the 2011 California Master Gardener Conference website

Months applicable: January, February, December

Tags: Best Practices, Fruits & Nuts, Techniques

Fruit Tree Harvest

If you have fruit trees that are ready to pick and more fruit than your family can use, please contact Village Harvest. Village Harvest is a non-profit volunteer organization in the greater San Francisco Bay Area that harvests fruit from backyards and small orchards, then passes it along to local food agencies to feed the hungry. They also provide education on fruit tree care, harvesting, and food preservation.

Months applicable: July, August

Tags: Best Practices, Fruits & Nuts, Trees & Shrubs

Fruit Tree Pruning

Winter is the best time to prune most deciduous fruit trees because the tree structure is easily seen once the leaves drop. Start by removing crossing branches, broken branches, and diseased wood. Clean out suckers, and light branches. Trim the branches that grow vertically. Then make cuts to produce the desired height and shape and to allow sunlight into the center of the tree. Not sure about the shape? UC has more information in Publication 8057, Fruit Trees: Training and Pruning Deciduous Trees. View a pruning video using the link below or refer to Fruit Tree Pruning.

Months applicable: January, February, December

Tags: Fruits & Nuts, Techniques

Fungus Gnats

Have you ever found yourself waving away a poorly-flying, small insect near seedlings or houseplants? Or noticed a swarm of tiny flies around a composting bin? Adult fungus gnats are nuisance pests, but in high numbers, the larvae can damage roots and stunt plant growth. They thrive in moist, organically-rich potting soil and can be found indoors at any time of year. The most effective control targets the larvae by eliminating excess moisture, especially by letting the surface of container soil dry between watering. Other control methods are discussed in the linked UC Pest Note.

For more information: Fungus gnats Management Guide

Months applicable: May, June, July, Any month

Tags: Invertebrates, Vertebrates

Fusarium Wilt

This is the most prevalent and damaging tomato disease. It also starts with the yellowing of lower leaves, but the yellowing may be only on one side (stopping at midrib) of the leaf or just one branch or one side of the plant. The older leaves will droop and curve downward. The yellow leaves wilt and die, gradually killing the whole plant. Sometimes a single shoot is killed before the rest of the plant shows any damage. More information at UC Pest Note on Fusarium Wilt.

Months applicable: June, July

Tags: Disease, IPM, Vegetables

Garden Planning in a Drought

Even when we get good winter rains, our summers are dry. So, water-wise garden planning is always a smart choice. We can prioritize the plants with more value, including food production or a long-term investment. If your existing plants are crowded, consider removing some so they don’t compete for water. This is a great time to get rid of any that you don’t really like. Why waste water on them? Don’t add new plants to your landscaping while we remain in a severe drought. Even drought-tolerant plants and California natives need extra water to get established.

More information: Drought: Gardening Tips

 

Months applicable: March, April, May, June

Tags: Waterwise Plants, Waterwise Tips

Garden Sanitation

Keeping the garden clean can help keep it healthy. Remove spent blossoms, fruit, and other plant parts as your plants finish producing. Dead and decaying plant parts can attract pests and give them safe places to breed. Insect pests damage plants directly by eating material or sucking out juices and nutrients, and they also spread diseases between plants as they move around. Weeds compete with desirable plants for water and nutrients and even sunlight, so remove them promptly. Older leaves of some plants, like squash vines, may naturally turn yellow and die. Removing them early allows the plants’ energy to go into the actively growing parts. Pick up fallen fruit that can attract rodents and can also return disease pathogens to the soil and plant. It’s particularly important to remove dried-up fruit “mummies” so that the fungal spores don’t spread. Prune dying tree branches before they can fall and do damage. Some flowering plants will produce more flowers if you remove spent blooms, a process called deadheading. You can leave healthy fallen leaves in place to form a mulch and decompose naturally, or you can rake them up and add them to the compost pile with other disease-free plant material. Do not compost diseased material.

Months applicable: July, August, September, Any month

Tags: Best Practices, Disease, Fruits & Nuts, IPM, Invertebrates, Trees & Shrubs

Garden Tools Prep

If you’re a warm season gardener and won’t be using your tools during the winter, now is a good time to get your tools ready for the off-season. Check your yard to make sure you haven’t left anything outside. Then clean dirt and sap from your tools and coat steel surfaces (check with a magnet if you’re not sure) with a light coating of oil to prevent rust. You can sharpen pruners and loppers. We have a video showing how to clean and sharpen tools.

More information: Tool Care Tips

Months applicable: November

Tags: Garden Tools

Garlic Harvesting

May–June is the time to stop watering your garlic. The tops will turn yellow and start to dry. Allow the bulbs to stay in the ground while the tops dry out, then carefully dig them up from mid-June to July. Cure the bulbs by placing them in a warm place with good air circulation, out of direct sunlight, for two weeks. Curing is an important step for good storage.

For more information: Garlic

Months applicable: May, June, July

Tags: Best Practices, Techniques, Vegetables

Gather Herbs for Drying

Itching to do something in the garden but not sure what? Cut back some of your oregano or mint and dry it. In our climate you will likely have herbs year-round, but drying some can help you when times are busy, or perhaps your relatives in the mid-west would love some home-grown, dried herbs, for a holiday gift this year. Simply hang it upside down in a cool, dry place. Why not try putting some on a cookie sheet on your dashboard to make use of the hot temperatures in your car without turning on an oven or a dehydrator?

Months applicable: August

Tags: Best Practices, Techniques

Geranium Care

Geraniums need very little water. Too much water can lead to stem rot, or, if combined with too much fertilizer, more leaf growth than flowers. Geraniums prefer a dry location. If this isn't possible, try growing them in pots.

Months applicable: June

Tags: Container Gardening, Ornamental Plants, Techniques

Giant Whiteflies

If you see white beardlike filaments handing from the leaves of your hibiscus, bird of paradise, or other plants, you may have giant whitefly. Another sign is the distinctive wax spirals on the undersides of the leaves. They can usually be controlled by washing them off or removing affected leaves. For more information see UC Pest Note on Giant Whitefly.

Months applicable: August

Tags: IPM, Invertebrates

Giant Whiteflies

Giant whiteflies were only discovered in California in 1992, but the infestation is now widespread in the San Francisco Bay Area. Plants most affected are ornamentals, such as begonia, hibiscus, bird of paradise, mulberry, and others. Adults produce spirals of wax primarily on the underside of leaves and lay their eggs in waxy bands which grow heavier as the population increases. Wax filaments grow to lengths of up to 2 inches, but in shielded areas, they can reach ten inches long! Even though affected plants weaken, they rarely die. Manage giant whiteflies by removing infected leaves, washing the undersides of leaves with strong streams of water, and encouraging beneficial insects to control populations.

More Information: Giant Whiteflies in Your Garden

Months applicable: June, July, August, September

Tags: Invertebrates

Going Native

Native shrubs, trees, and flowers are well-adapted to our climate and soil, and support native butterflies and bees and other wildlife. They are drought-tolerant once they are established, but need adequate water for the first year or two to establish a strong root system that will help nourish the plant for years to come. Planting them in the fall gives them time to settle in before being hit by the heat of the summer sun. Consult Water Wise Plants and the California Native Plant Society for more information.

Months applicable: October, November

Tags: Ornamental Plants, Waterwise Plants, Waterwise Tips

Gophers

Have you ever watched a plant wiggle and then disappear underground right before your very eyes? That’s the work of a gopher. You don’t often see them because they spend most of their time in underground tunnels, but you see the damage they do by chewing on plant roots or irrigation lines. One way to distinguish them from other soil-dwelling vertebrate pests is by the crescent-shaped mounds of dirt they make when they dive back down. Fresh mounds of moist soil are an indication of recent activity. They do not hibernate, so they are busy year-round. They can be eliminated through trapping and dispatching. Gophinator, Macabee, and Cinch traps specifically designed for gophers are the most commonly used. You can plant trees and shrubs in gopher baskets in the ground to protect their roots. You can also line the bottom of raised beds with hardware cloth to keep the gophers from burrowing up into the beds.

More information: Gopher Pest Note

Months applicable: June, July, August, Any month

Tags: IPM, Techniques, Vertebrates

Grass Cycling

Leave the clippings on the lawn when mowing. This provides nitrogen for the lawn. Mow frequently so that no more than 1/3 of the length of the grass blade is cut in any one mowing. Grass decomposes rapidly and very little thatch is formed. Small amounts of thatch can actually be beneficial to a lawn, serving as a mulch. Many parks and golf courses have been doing this for years. Other uses for grass clippings include mulching for weed control and as a great addition to your compost pile. There are some cities that no longer will allow grass clippings in their dumps.

Months applicable: June, July, August, September

Tags: Techniques

Gray Mold (Botrytis)

Botrytis is gray or brownish fuzzy mold that can attack a wide variety of plants. It likes flower petals, ripening fruits and vegetables, as well as leaves and stems. The spores are spread through the air. It is most severe when there's high humidity and may start forming on decaying matter. According to the UC Pest Note on Botrytis Blight, it is important to remove debris and prunings from the ground. You may even have to pick up flowers daily. Avoid overhead watering.

UC also has information about Gray Mold on Strawberries.

Months applicable: February

Tags: Disease, Fruits & Nuts, IPM, Ornamental Plants, Vegetables

Growing Peppers

As soon as average night time temperatures are above 55° F, peppers can be added to the garden. Before that time, they can be started indoors. Make pepper more productive by planting different varieties closely together. You will get more peppers per square foot because the plants support each other and provide protection from sunburn. Plus, they look lush and beautiful. After planting, it is a good idea to remove flowers and fruit from large-podded plants the first four to six weeks to encourage deeper roots and more foliage. Learn more pepper tips by consulting our Growing Great Peppers and Chiles page.

Months applicable: May, June

Tags: Best Practices, Techniques, Vegetables

Growing Purple Carrots

If you only buy carrots at the supermarket, you may think that they are all orange. It is believed that carrots were originally purple, with orange becoming popular through Dutch breeding. Several colors are now available at Farmers’ Markets and by growing your own. Springtime is a good time to start carrots from seed. Transplanting is not advised because you can easily damage the roots which are the relevant plant part. Loose soil is important so that the carrots will grow straight. Scatter the seeds over the soil with as thin a covering as possible, keep moist until germination, and harvest when the tops expand to a good size. The Master Gardeners have done germination and growing experiments with different varieties and soil blends. Covering seeds with a thin layer of vermiculite yielded the fastest and highest rate of germination. Carrots are slow to germinate and could take as long as 3 weeks. Thin to 2 or 3 inches apart. For growing, a soil blend of 1/3 compost and 2/3 soil produced higher-weight carrots than blends with half of the soil replaced with either sand or perlite.

Some common problems are twisted roots from planting too close together, forked or deformed roots from clods and rocks in the soil, a hairy root from too much nitrogen and splitting from too much water.

More Information: Growing Carrots

Months applicable: February, March, April, September

Tags: Techniques, Vegetables

Growing Transplants from Seeds

Many summer vegetables can be started now from seed indoors or in a greenhouse. The ground is still too cold for summer seeds to germinate or for the plants to go into the ground. Depending on the weather we get this spring, it will likely be May or June before the soil is warm enough. The soil in containers or raised beds will warm up earlier in the season.

Starting plants in pots will give them time to get stronger before putting them near potential pests. It will also allow you to continue enjoying current cool-season vegetables.

Information found on the seed packages will show which conditions are best for germination. Peppers in particular germinate best with high soil temperature. Using a heating pad is one way that this can be done indoors.

Be sure to provide light once the seeds germinate if the seedlings are not in natural sunlight. Seedlings with insufficient light will grow tall and thin and leggy and will not be as strong.

When reusing pots for seed starting, prevent the spread of plant diseases by making sure they are clean. Remove any remaining soil and cobwebs; then clean with a 10% bleach solution: 1 part bleach to 9 parts water.

If they are growing too large for the pots they are in, transplant them into larger pots. The same can be done for seedlings purchased from a nursery. Transplant them on the ground as suggested under "when to plant" for each vegetable tomatoes, peppers, cucumbers, squash, and melons.

This video provides more details on raising your own seedlings.

Months applicable: February, March, April

Tags: Vegetables

Growing Vegetables in Containers

Container grown vegetables can be decorative as well as good to eat. Almost any vegetable can be grown in a container if given the proper care. Eggplant, peppers, tomatoes, lettuce, onions, carrots, cucumbers and herbs do well. Use our Vegetable Planting Chart to decide when to plant.

One of the biggest problems is that containers dry out very fast and nutrients wash away. Both are solvable. Do not use clay pots, which dry out quickly. Plastic, composite or wooden half-barrels are good, but avoid dark colors that can absorb heat. Vegetables like a roomy container.

There must be drainage holes in the bottom but it is not recommended that you put pebbles or broken crockery in the bottom. Use a good commercial potting mix, not planter or planting mix. Group the containers together so they will shade one another.

The hot summer sun can heat the soil to unhealthy levels. Water whenever the soil is dry. You can test by digging your fingers into the dirt. You may have to water more than once a day. A simple drip system is easy to install and will make your container garden almost foolproof. Fertilize every week with a water-soluble fertilizer.

Months applicable: February, March, April, October, November

Tags: Techniques

Gummosis in Stone Fruit

Gummosis is a general term that refers to the oozing of sap. The most common cause in stone fruit is a fungal disease called Cytospora canker. The fungus infects the tree through wounds and the sap is usually amber-colored and free of sawdust. Tree borers can also cause gummosis. In this case, the sap may contain sawdust or other debris. Mechanical injuries and sun scald can also cause sap to leak and open the tree to infection. Advice to prevent and deal with it includes following good pruning practices, protecting tree trunks and limbs from sun scald, and pruning out diseased wood past the point of infection. More information from Utah State University in their summary of cytospora canker.

Months applicable: May

Tags: Fruits & Nuts, IPM

Hand Pollinating Squash

Squash plants have male and female flowers on the same plant. Male flowers have a long thin stem while female flowers have a small swelling behind them like a baby squash. The female flowers require pollen from the male flowers for squash to form. Usually, bees and other insects will do the job for you, but if you don’t have enough natural pollinators in your garden, you can do it yourself. Peel away the petals, then touch the male anther to the female stigma to transfer pollen, as shown in the photo. It is important to use only freshly opened flowers. They open early in the morning and are receptive for only 1 day.

If the squash grows a few inches and then starts to die, it’s probably because the pollination wasn’t successful.

More information: Fruit Setting Problem in Cucurbits

Months applicable: July, August

Tags: Techniques, Vegetables

Harden Seedlings

Seedlings grown indoors or in a greenhouse are tender because they have been sheltered from direct sun and outdoor conditions. You need to acclimate them to the great outdoors, a process called hardening, before planting them into the garden. Start by giving them short exposures to full sun and cool nights, gradually increasing the amount of time. Seedlings can dry out quickly, so be sure to keep them watered, especially with hot or windy weather. Protect them if nights are cold. After about two weeks, they should be ready to start life in the garden.

More information: Hardening Transplants

Months applicable: April, May

Tags: Best Practices, Garden Basics, Techniques, Vegetables

Harvest Kiwis

Pick kiwis in late fall while is still hard like an avocado, softening at room temperature. Watch the vine for signs of ripeness. A few fruit will turn soft or the skin color goes from greenish to full brown. Fruit can be left on the vine after leaves have fallen. You can store in the refrigerator for up to 4 months or at room temperature for about 2 weeks. More details about Kiwifruit Culture is provided by the California Rare Fruit Growers.

Months applicable: November

Tags: Fruits & Nuts

Harvesting Oranges

There’s a simple way to know whether your citrus fruit is ripe: taste it! Citrus varieties differ in when they first ripen and how long the fruit holds on the tree. Harvest dates depend on the variety and the climate. For example, the normal fruit season is winter for Navel orange, and summer for Valencia orange. Until you are familiar with your particular tree, sample a fruit periodically to see if it suits your taste. Allow fruit to ripen fully on the tree, as citrus does not continue to ripen once it’s picked.

More information: Harvesting and storing citrus

Months applicable: January, February, July, August, September, October, November

Tags: Fruits & Nuts, Techniques

Harvesting Sweet Potatoes

Hopefully the timing of your sweet potato harvest will work out for Thanksgiving dinner! They are usually ready 90-100 days after planting, when the end leaves start to yellow. You can dig down a little to see if the potatoes are large enough, but dig carefully or use your hands to avoid accidentally cutting the potatoes. If you plan to store them, cure them in a warm, humid environment for a couple weeks.

Months applicable: November

Tags: Vegetables

Healthy Tomatoes

Months applicable: July, August

Tags: Best Practices, Disease, IPM, Techniques, Vegetables

Herbs

Months applicable: March, April, May, September, October

Tags: Best Practices, Herbs

High Yield Vegetables

Months applicable: April, May, June

Tags: Best Practices, Vegetables

Holiday Ideas

Prune your evergreen trees and shrubs now and use the cuttings for holiday wreaths.

Christmas cactus, poinsettias, cyclamen, kalanchoe, amaryllis and more help make the house look festive at this time of year. They prefer cool temperatures, so find a place for them away from a heating vent. To avoid over watering, check the soil and give them water only when dry.

Consider a living Christmas tree that can later be planted in your garden. A smaller tree doesn’t have room for as many ornaments, but is more likely to adapt well when planted outdoors. You can even rent a tree from Our City Forest as it's on its way to a permanent home in the community.

You can bring some of the beauty of your garden inside to decorate your home for the holidays. Consider some of these seasonal items for tree ornaments, mantle decorations, garlands, and wreaths: laurel leaves, lemons, pine cones, nuts, pyracantha berries, eucalyptus pods, grape vines, rosemary, and rose hips.

Months applicable: December

Tags: Best Practices

Houseplants Repotting

If you’ve noticed the soil in your houseplants is drying out quickly, or leaves are turning yellow, check whether the plant is rootbound. The most obvious clue is roots growing from a drainage hole or on top of the soil. Especially vigorous roots can break pots! UC scientists recommend choosing a new container no more than 2 inches larger in diameter, with drainage holes. Don’t add stones to the bottom – they hinder drainage, causing root rot. Use new potting soil, not garden soil that may harbor diseases or pests. Unwind and trim roots that circle the pot. Add soil to the container, keep the root ball an inch below the rim, and water well.

More information: Repotting Houseplants

Months applicable: January, February, December, Any month

Tags: Garden Basics

How to Attract and Maintain Pollinators in Your Garden

UC ANR has a publication titled "How to Attract and Maintain Pollinators in Your Garden" that discusses the benefits of providing flowers for pollinators and has a list of pollinator plants that are successful in most California gardens.

Months applicable: Any month

Tags: Beneficial Insects, Best Practices, Ornamental Plants

How to Tell if Fruits and Vegetables Are Ready to Pick

The UC Davis Postharvest Technology website was designed for commercial growers, but the information on how to tell When Fruits and Vegetables are Mature is handy for home gardeners as well. There's also information about how to Store Fruits and Vegetables for Better Taste.

Months applicable: July, August, September

Tags: Best Practices, Fruits & Nuts, Techniques, Vegetables

Identifying Beneficial Insects

A whole army of insects is in your garden ready to help your plants thrive. Pollinators, like bees and butterflies, help plants produce fruit. Lady beetles and lacewings are predators that hunt, kill, and eat insects. And parasites, like certain wasps, develop within a pest’s body and then kill them. Such violence! The trick is knowing which insects are friends or foes. To identify the insects on your own, take pictures of them and any eggs or larvae (check the undersides of leaves). Then zoom in for a closer view and use this site to help you identify beneficial insects.

More information: Beneficial Insects

Months applicable: March, April, May, June, July, August, September

Tags: Beneficial Insects

Identifying Weed Seedlings

Winter rains are wonderful but they also bring winter weeds, and the sooner you deal with those, the better. In fact, pulling or hoeing them as soon as they sprout is both easy and effective. However, those young weeds may not bear much resemblance to their mature forms. To see a large number of weeds in their youthful forms, refer to the Common Weed Seedlings documents. With a little practice, you can train your eye to spot these weeds as soon as they pop up.

Months applicable: January, Any month

Tags: Weeds

Inspect Roots When Planting

If you’re adding plants to your garden this spring, check the roots before putting them into the ground. Two things are particularly important. First, look for circling roots, which can eventually strangle the plant. Straighten them out as much as possible and consider pruning them if they’re too big to spread. Second, note where the roots start growing and plant at that depth, or slightly higher to allow for some settling. If planted too deeply, plant roots cannot get enough oxygen to grow and may suffocate and die. Planting too shallow can result in root damage from exposure and excessive drying.

More Information: Fix Those Roots Before You Plant

Months applicable: February, March, April, May, September, October, November

Tags: Best Practices, Garden Basics, Techniques

Irrigate in Circles and Spirals

When you add a new plant to your landscape, it’s important to keep the root ball well watered until the roots start extending into the surrounding soil. The root ball can dry out even when the surrounding soil is moist, so an irrigation emitter is often placed right at the base of the plant. However, the irrigation needs to change as the plant matures. As the plant grows, move the irrigation away from the base and instead start irrigating in circles or spirals around it. For trees and large shrubs, continue expanding the irrigation spiral as they grow.

For more information: Help Your Trees Survive the Drought

Months applicable: May, June, July, August

Tags: Best Practices, Fruits & Nuts, Irrigation, Ornamental Plants, Trees & Shrubs

Irrigation Maintenance

Check your watering system regularly to make sure it’s working properly. Sprinklers and emitters that are plugged up or misdirected can cause problems for the plants they’re supposed to water, and broken emitters and hoses waste water. Get ready for the growing season by starting a watering cycle for each zone of your controller and visually checking its operation. If you’d like help, Valley Water offers a free evaluation service for properties less than ½-acre in size. Use the link below to schedule a survey.

Water Wise Outdoor Survey

Months applicable: March, April, September, October

Tags: Best Practices, Techniques

Kale

Months applicable: May, June, July

Tags: Best Practices

Keep Foliage after Bloom Fade

To keep bulbs/corms/rhizomes/tubers blooming each year, leave the plant’s foliage in the ground long after the blossoms have withered. That’s because the foliage needs to photosynthesize to store energy in the bulb for next year’s blooms. Deadhead the spent flowers by cutting the stalks from the finished blooms all the way back to the base, Then wait for the foliage to die back and turn yellow before removing it. Some people tie the leaves together to tidy the garden, but that’s not advised because it limits the light needed for photosynthesis. As an alternative, intersperse annuals to hide the foliage until it can be removed.

If the plants seemed crowded and the flowers were getting smaller, carefully dig them up, separate the bulbs, and replant them with greater spacing. Toss any bulbs/corms/rhizomes/tubers that are mushy or show other signs of rot. And continue to enjoy easy-maintenance flowers year after year.

More information: Basic Bulb Care

Months applicable: March, April, May, June

Tags: Ornamental Plants, Techniques

Keep Up With Your Vegetable Harvest

The middle of summer is a particularly busy time of year for vegetable gardeners. It can be a challenge to keep up with harvesting—beans can become swollen and tough and zucchinis can become baseball bats! It's particularly important to keep up with plants such as beans because the production of mature seeds (inside the pod) signals the plant to stop producing. Tomatoes can split and rot on the vine in exceptionally hot weather.

Months applicable: July, August

Tags: Abiotic Disorders, Best Practices, Techniques, Vegetables

Keep Watering Until the Cool Weather Arrives

September is still a warm month in Santa Clara County. Continue watering established trees and shrubs until temperatures cool down. As a rule of thumb, trees should have a couple of deep waterings during the summer, if you haven't done that, now is a good time. Use a soaker hose or drip hose around the drip line of the tree and slowly water for two to three hours. Mature fruit trees need a bit more, fill the surrounding basin every 3–4 weeks, young fruit trees need water every couple of weeks.

Months applicable: September

Tags: Techniques

Lady Beetle

We all know that lady beetles are good for the garden. Make sure you can recognize the larval stage because this life stage eats even more aphids than the adult form. Lady beetles lay their distinctive yellow eggs near a food source such as aphids. The larvae grow quickly, then pupate into the familiar adult form (but there are actually many varieties of lady beetles). It’s better to attract lady beetles to your garden rather than buying and releasing them. Purchased lady beetles generally fly away, and the process of collecting them in the wild is often destructive. To attract lady beetles, refrain from spraying insecticides, grow flowers that attract beneficial insects, and leave some aphids for them to eat.

For more information: Aphid Eaters

Months applicable: March, April, May, June, July, August

Tags: Beneficial Insects

Late Tomatoes

How many more edible tomatoes can you expect to get this year? Any tomatoes currently on the plant are likely to ripen nicely in the next month or so. Current blossoms may lead to good tomatoes, mealy tasteless tomatoes, or none at all. It depends on the weather. Many of us have taken the gamble and eaten tomatoes into December and beyond, more for the challenge and bragging rights than for exquisite flavor. But a cool fall can affect production and quality, and some gardeners start removing blossoms now. This allows the plant’s energy to go into the existing fruit. If we have another mild winter like last year, the plant could survive and produce another crop of tomatoes next summer. We each make our own decisions based on our guesses, hopes, energy level, and available garden space.

More information: Growing tomatoes in the home garden

Months applicable: September

Tags: Techniques, Vegetables

Lawn Alternatives

Do you have a traditional lawn? Would you like something that doesn’t need regular mowing? Something that uses less water? If you’re not ready to completely remove your lawn, walkable alternatives include California native options of red fescue and meadow sedge, as well as other alternatives like white clover, UC Verde buffalograss, Kurapia, Dymondia, and thyme.

For more information: Lawn & Lawn Alternatives

Months applicable: March, April, May

Tags: Lawns, Waterwise Tips

Lawn Care

As the weather changes, many of our management techniques have to change. Lawns need more water as the temperature increases and the humidity lowers. But please don't overwater; too much water is wasted by going below the root zone or running off. Adjust timers monthly throughout the year. In the warmer months, lawns may need water twice a week. It is not good to water daily. If watering is daily and brief, the roots will stay shallow and susceptible to drying and burning. Be sure to water as early in the morning as possible to avoid evaporation. This also helps reduce fungal diseases by giving the grass time to dry out during the day. Poor watering practices are the main reason for dead and dying areas in lawns and a common source of urban runoff.

Make sure you are mowing to a height appropriate for your type of grass. Mow frequently enough so that only one-third of the leaf is removed at any one time.

Fertilizing is important, even if you are grasscycling, which only provides about 20% of a lawn's fertilizer needs. Grass is all leaf, so the primary nutrient needed is nitrogen. Keep on top of weed removal.

Thatch is the layer of living and dead grass material (blades, rhizomes, stolons) that can build up on the surface of the lawn. A thin layer protects the soil surface and shallow roots from drying out from the sun, but a thick layer prevents water from getting through. You can remove dead grass material on the soil surface with a special thatch rake to allow water to reach the roots more easily.

More Information: The UC Guide to Healthy Lawns

Months applicable: May, June, July, August, September, October

Tags: Best Practices, Irrigation, Lawns, Techniques, Waterwise Tips

Leafcutter Bees - a Beneficial Insect

Do your rose bush leaves have smooth round holes in them? The likely culprit is the female leafcutter bee. The bee cuts smooth round or oval leaf fragments and uses them to line each underground brood cell that she fills with nectar and pollen. When the cell is ready, a single egg is sealed inside. The larva pupates (matures) in the chamber and emerges in the spring.

Rose leaves seem to be their favorite. The hole in the leaf is much larger than an ordinary caterpillar would make and is very smooth as if a miniature cookie cutter was used. The bee can chew off a leaf fragment in less then a minute with its sharp jaws.

Like all bees, leafcutter bees are important pollinators and should not be killed.

Months applicable: September

Tags: Beneficial Insects

Leafminers

Watch for damage from leafminers on many types of plants, including leaves of vegetables and commonly on citrus. Eggs can either be inserted into leaves or laid on the surface of leaves. In either case, the larvae feed between leaf surfaces, creating a "mine". If eggs are on the surface of the leaf, they can be rubbed off before hatching.

Plant resistant species or varieties. Small seedlings can be protected by protective cloth. On plants such as cole crops, lettuce, and spinach, clip off and remove older infested leaves. Place leaves in plastic bag, and put bag in trash. Leafminers are often kept under good control by natural parasites. Insecticides are not very effective for leafminer control. See UC Pest Note on Leafminers for additional information.

Months applicable: October

Tags: Disease, IPM, Invertebrates, Vegetables

Leafy Salad Plants

Harvest your leafy vegetables early and often. Many leafy vegetables will bolt (go to flower) quickly if not harvested. When you harvest lettuce or similar greens, remove only the outer, older leaves. New leaves will continue to grow from the center, and you'll be able to eat salads all winter. Harvest head lettuce all at once when the head is full and firm. Watch for signs that plants are getting ready to bolt. That’s the signal it’s time to harvest the entire plant.

Months applicable: January, February, March, November, December

Tags: Best Practices, Vegetables

Limes

Limes are easy to grow in our area and make a pretty addition to the landscape. They don’t take up as much space as some other citrus and can grow well in our native soil with plenty of sun. They need some fertilizing and occasional protection from the cold. Bearss Lime is a popular variety that has fruit ripening now. Other favorites include Mexican Lime, Australian Finger Lime, and a Limequat hybrid. Most limes are yellow when fully ripe and have a higher juice content at this stage; most limes in stores are green because they have a longer post-harvest life or shelf life. A tan, leathery sunken area at the end of the fruit is called blossom end rot in citrus. It can come from insufficient water, preventing calcium from getting all the way to the ends of the fruit (similar to blossom end rot in tomatoes.) You can freeze the fruits whole for year-round margaritas or whatever it is you do with your limes. Freezing weakens the cell walls, which makes it even easier to juice the limes after thawing.

More Information: Growing Citrus Fruits

Months applicable: January, November, December

Tags: Abiotic Disorders, Fruits & Nuts, Techniques

Manage Pests with "Integrated Pest Management"

Months applicable: Any month

Tags: Disease

Melons

By this time the vines have spread out and there are flowers everywhere. A foliar spray of a water-soluble fertilizer will give them a boost now. Keep the water flowing as they are one of the thirstiest plants you can grow. You can set young melons on the top of inverted cans (coffee cans, tuna cans, etc.) to warm them faster and more evenly. Punch a hole in the bottom of the can so water won't puddle and rot the melon. Melons will begin ripening in August. How will you know when it's ripe? The background color behind the netting will turn from green to tan. The stem will slip right off with just a light touch. Last but not least. let your nose tell you if it's ripe. Smell the stem end; it should have a wonderful melon aroma. The color and smell test also works well in the grocery store.

Months applicable: July

Tags: Fruits & Nuts

Mistletoe

The dense mass of leafy balls high up in trees is broadleaf mistletoe. There are multiple species in California, both native and introduced. Mistletoe is a hemiparasite, meaning it can photosynthesize on its own, but draws nutrients and water from its host. Birds feast on the translucent white berries, spreading the sticky seeds to new locations. When a seed sprouts, it sends out a modified root that penetrates the tree’s bark. A healthy tree can support a moderate infestation, but if the infestation is heavy or if a tree is stressed by other factors such as disease or drought, it can kill the tree.

Months applicable: December

Tags: IPM, Techniques, Weeds

Moles

Months applicable: August, Any month

Tags: IPM, Vertebrates

Mosaic Virus

Mosaic virus on squash and cucumber plants is a disease spread by aphids and cucumber beetles. The leaves become rough and mottled, the plant becomes stunted and the fruit can be whitish. Pull the plant and put it in the trash. Do not compost. For more information see UC Pest Note on Squash Mosaic Virus.

Months applicable: September

Tags: Disease, IPM, Vegetables

Mulch Bare Soil Before Rains

Mulch isn’t just for the summer. Yes, it’s good for conserving soil moisture and keeping the ground cool, but it’s important in the rainy season too. Bare soil that’s open to rain, wind, and sun becomes compacted and hard. Rain tends to run off instead of getting absorbed. Compare a patch of bare soil with one that’s been deeply mulched, and you’ll see the difference. An organic mulch that slowly decomposes keeps the soil beneath it moist and loose, plus it will suppress the weeds that will be sprouting with the rains.

More information: Impact of Mulches

Months applicable: October, November

Tags: Best Practices, Soil

Mulch to Conserve Water

A 3 to 4" layer of mulch can reduce watering needs by as much as 50 percent. Mulch reduces water evaporation and keeps soil temperatures down during hot summer months. In addition, mulch reduces the number of weeds, makes it easier to control weeds that do grow, and protects the soil from compaction. A variety of mulches are available. Organic mulches such as arborist chips and bark nuggets break down and improve soil quality over time. You can find free wood chip mulch from local arborists by searching online, such as “free wood chips near me”. Place mulch away from the street curb to prevent heavy rains from washing it into storm drains. Also keep mulch away from the trunks of woody trees or shrubs to avoid decay problems.

More information: Mulching with Organic Materials

Months applicable: April, May, June, July, August, September, Any month

Tags: Best Practices, Fruits & Nuts, Ornamental Plants, Trees & Shrubs, Vegetables

Mushrooms

Sometimes it seems like there are mushrooms all over: mushrooms in the lawn; mushrooms on the trees; mushrooms in fertilizer; mushrooms in the woods; there is even mushroom compost available. How do you know which mushrooms are desirable and which are not? This can be a life or death determination, both for you and for your plants. Mushrooms are the fruiting bodies we see of fungi which can be widespread and hidden underground or inside plants. Fungi play a beneficial role in decomposition and in providing nutrients to garden plants. Mushrooms in the lawn can be a sign of overwatering, so check the irrigation and drainage. You don't need to remove the mushrooms except to protect young children and pets from eating them. If cultivating or harvesting mushrooms to eat, be sure that you know it is not a poisonous variety.

Months applicable: January, February, December

Tags: Irrigation

Native Wildflowers

Native California wildflowers herald the beginning of spring — and the time to plant them is ahead of the winter rain. Besides their showy display, they’re a habitat for local pollinators and a great way to cover up bare spots. If that’s not enough, they also require little care. Just select a well-drained and sunny site, remove weeds, and lightly rake the surface of the soil. Hand disperse seeds and lightly cover with soil, no more than about ¼ inch. Gently tamp them down with the back of a rake and water. After that, let Mother Nature take its course — we hope with some rain!

More information: Native Wildflowers

Months applicable: September, October, November

Tags: Ornamental Plants, Waterwise Plants

Neem Oil

Neem products are derived from the neem tree, Azadirachta indica. But most neem products on the market lack the active insecticidal ingredient azadirachtin. Neem oil, called “clarified hydrophobic extract of neem”, is still effective as horticultural oil for smothering juvenile insects and may be effective in suppressing powdery mildew. But it won’t be effective in cases where azadirachtin is required. Like any horticultural oil, neem oil can potentially damage plants by burning their foliage and should be sprayed at dawn or dusk to protect bees and other pollinators. When using any pesticide, it’s important to reach an accurate diagnosis first and understand that no product helps solve every plant problem. Neem is not a cure-all.

More information: More about Neem

Months applicable: Any month

Tags: Best Practices, Disease, IPM, Invertebrates, Ornamental Plants, Vegetables

Nematode Control with Marigolds

Some varieties of marigold can suppress certain damaging nematodes while adding color to the garden. The Tagetes species suppress root knot and lesion nematodes. French marigolds, including Nemagold, Petite Blanc, Queen Sophia, and Tangerine, are most effective. Avoid signet marigolds, T. signata or tenuifolia, because nematodes will feed and reproduce on these. Marigolds don’t work well against the northern root knot nematode, Meloidogyne hapla, a species common in areas with cool winters. The effect of marigolds is greatest when grown as a solid planting for an entire season. When grown along with annual vegetables or beneath trees or vines (intercropping), nematode control usually isn’t very effective. To prevent marigold seed from getting in the soil, cut or mow the plants before the flowers open. As with other cultural control methods, nematode populations rapidly will increase as soon as susceptible crops are grown again. Learn more at the UC Pest Note on Nematodes.

Months applicable: June

Tags: IPM, Invertebrates, Vertebrates

New Trees Staking

Not all new trees even need to be staked. Only stake if necessary for protection, anchorage, or support. Don't place the stakes too close to the trunk of the tree. Place stakes on opposite sides of the tree, outside the root ball. Make sure the stakes don’t rub on the trunk or branches. Ties should be added no higher than necessary to support the trunk. This allows as much freedom to move as possible, and movement builds trunk strength. Inspect the tree regularly to make sure there’s no damage. Remove the ties and stakes when the tree can stand on its own, generally after a year or so.

Months applicable: January, February, March, April

Tags: Best Practices, Fruits & Nuts, Techniques, Trees & Shrubs

Oak Root Fungus

This fungal infection, Armillaria Mellea, also known as mushroom root rot, honey fungus and shoestring fungus can cause foliage to become sparse and eventually kill the tree. The white or cream-colored fungus will grow between bark and wood of roots and up into the lower part of the tree trunk. It smells like your typical grocery store mushroom.

In spring or fall there may be mushrooms growing around the base of the infected tree. If the disease has not progressed too far, you can cut out infected tissue and expose the base of the tree and roots to air. Reduce watering especially close to trunk. No chemical treatment is known to be effective.

Plants Resistant or Susceptible to Armillaria mellea, The Oak Root Fungus by Robert D. Raabe contains more detailed information. The UC Master Gardener video Revealing Root Rot can help with detection of two common root pathogens and provide guidance on how to reduce the spread.

Months applicable: December

Tags: Disease, IPM, Trees & Shrubs

Oakworm

This is a pest of California Live Oaks. The adult oakworm moth is tan-to-gray colored with a wing span of about an inch. It lays white eggs twice a year that turn reddish or brown before hatching. The first hatch is in November and overwinters on the leaves, growing and eating more as the weather warms. At full size, the larva is about an inch long with a yellowish green body, dark stripes down the side and large brown head. Outbreaks occur every eight to ten years in the Bay Area. In late March or April, look for little green pellets (droppings) falling from oak trees. A second generation of eggs hatches in mid to late summer. Trees may suffer no permanent damage beyond being unsightly. If you cannot tolerate the worms and their mess, further treatment methods are outlined in the UC Pest Note on California Oakworm.

Months applicable: April

Tags: IPM, Invertebrates, Trees & Shrubs

Oleander

Months applicable: September

Tags: Ornamental Plants, Waterwise Plants

Olive Harvest

Harvest olives grown for the table when fruit is still green. Olives grown for oil can be harvested when the fruit is yellow to reddish-purple and the flesh is still green-yellow. Continue irrigating until first rains. Apply fixed copper to prevent peacock spot before the first major rain, and be sure to wash the fruit before use or wait until after harvest to spray.

Months applicable: October

Tags: Fruits & Nuts, Techniques, Trees & Shrubs

Onions

This is a good time to plant onions for nice big bulbs. Onions are biennial plants which means that they are programmed to go to seed in their second year. If they are planted too early in the year and grow too large before cold weather hits, they can be tricked in the spring into acting as if they are in their second year. This means that they will go to seed soon and put their energy into reproducing themselves rather than into growing large bulbs. Ideally, they should be no bigger than the thickness of a pencil when the cold weather causes them to go dormant. Plant onions from seeds if earlier in the fall or transplants if later. They do best in moist, well-drained soil. Harvest bulbs in the summer when the tops die back. You can plant green onions at any time and harvest them whenever they are about a quarter to half-inch in diameter.

More information: Growing onions

Months applicable: November, December

Tags: Techniques, Vegetables

Organic Soil Amendments

After harvesting remaining summer crops, add amendments such as blood meal, alfalfa pellets or fish emulsion to replenish nitrogen in the soil. Add a layer of compost to all existing garden beds to provide needed nutrients for winter crops. Be sure to leave some areas of native soil for ground-nesting bees.

Months applicable: October

Tags: Best Practices, Soil

Overgrown Shrubs

If your shrubs have become too large for their allotted space, you may be able to resize them rather than replace them. Many woody shrubs can be cut back to within a few inches of the ground. These include Buddleia (butterfly bush), Artemisia (wormwood), and Salvia leucantha (Mexican sage). Maybe worth a try before replacing the plant!

Months applicable: February

Tags: Best Practices, Techniques, Trees & Shrubs

Paint Fruit Trees to Prevent Sunburn

After deciduous fruit trees have dropped their leaves, paint tree trunks with white latex paint diluted 1:1 with water to prevent sunburn. Preventing sunburn helps trees resist invasion by shot hole borers, which are tiny beetles that boreholes and lay eggs in the cambium layer of the tree. When the eggs hatch, young larvae feed and excavate tunnel galleries in the wood. For more information about identification and control see UC Pest Note on Shothole Borer.

Months applicable: November, December

Tags: Best Practices, Fruits & Nuts, IPM, Invertebrates, Trees & Shrubs

Peach Leaf Curl Preventive Care

Have your peach or nectarine leaves ever looked like this? These puckered leaves are a classic springtime symptom of peach leaf curl. Severe cases can substantially reduce fruit production. Prevent this disease by applying a copper-based fungicide shortly after the leaves drop. Use a second application in late winter if there’s a lot of winter rain. Once the blossoms open and leaves appear, it’s too late to do anything. Spraying during the growing season won’t help. If you haven’t seen this on your tree, you may have a resistant variety. If so, there’s no need to spray.

More information: Pear Leaf Curl

Months applicable: January, February, November, December

Tags: Disease, Fruits & Nuts, IPM

Peas

An old American tradition says that planting peas on St. Patrick’s Day will bring good luck at harvest time. But the best planting date actually depends on the climate where you live. Planting on St. Patrick’s Day in the northeast may lead to a second planting weeks later when frost gets the first batch. Yet in warmer climates like ours, we can plant weeks earlier and may even be eating peas from the garden on St. Patrick’s Day. (We can also plant them here in the fall.) You may want to soak the seeds overnight to help get them ready to germinate. They can be planted directly in the ground, about half an inch deep. Keep the seeds evenly moist until they start to sprout. Provide a trellis or some kind of support for the vertical vines if you are growing pole peas; bush peas can stand on their own.

Months applicable: February, March, August, September

Tags: Techniques, Vegetables

Pepper Weevil

The pepper weevil is a small insect (about ?" long) but is a worldwide problem for pepper growers. It has been an increasing problem in Santa Clara County. Female weevils chew holes on buds or at the base of young fruit and then lay their eggs inside. The larvae develop inside the fruit causing damage and leaving excrement.Then they chew their way out making the exit holes seen in the photo. Pepper weevils sometimes also cause premature fruit drop. They affect all kinds of peppers and chiles, but a recent local study showed the most problems with bell peppers. To reduce the population, clean up and discard any dropped fruit and peppers with holes near the stem.

More information: Pepper Weevil

Months applicable: July, August, September

Tags: Invertebrates, Vegetables

Peppertree Psyllids

This pest can cause damage to California pepper trees. The damage is done when the insect is in its immature stage. They make doughnut-like pits on leaves that wrinkle or twist the leaves as well. Parasitic wasps can provide satisfactory control. See the UC Pest Note on Psyllids for more information.

Months applicable: December

Tags: Disease, IPM, Invertebrates

Perennials and Bunch Grasses

Months applicable: January, February, December

Tags: Best Practices, Ornamental Plants, Techniques

Persimmon Harvesting

Persimmon season is here. The skin of the fruit turns orange when fully ripe. The flat bottomed Fuyu persimmons will still be fairly firm when ready and can be eaten raw like a crispy apple or sliced up and cooked into an apple-style pie. Fruit that falls from the tree early may continue to ripen on the counter despite the green skin. Heart-shaped Hachiya persimmons turn almost jelly-like inside when ripe. It is best to eat raw by cutting it in half and digging it out with a spoon. They can also be used in baking. If you eat an unripe Hachiya persimmon, you will gain a new understanding of the word “astringent”! To protect the persimmons from birds and squirrels, it is necessary to wrap the tree with bird netting or cover it in a structure made with chicken wire before the fruits are ripe.

More information: Persimmons

Months applicable: October, November

Tags: Fruits & Nuts

Pest Alert - Spotted Lanternfly

Months applicable: Any month

Tags: Invertebrates

Pet Safety in the Garden

Months applicable: Any month

Tags: Best Practices

Picking Pomegranates Properly

Picking pomegranates at the right time is important because they don’t continue to ripen after harvest. Clues to watch for: a deepening color of the fruit, a metallic sound when tapped, and softening skin that can be scratched with gentle pressure. When harvesting, clip the stem close to the fruit instead of pulling it off the tree. This prevents open wounds that may rot. Pomegranates are susceptible to splitting when watered unevenly, so if you've reduced irrigation because of the drought, you may want to harvest them quickly once winter rains start.

More information: Pomegranates, California Rare Fruit Growers

Months applicable: October, November

Tags: Fruits & Nuts, Techniques

Picking and preserving oranges

Months applicable: April, May

Tags: Fruits & Nuts

Pinch Your Basil

Pinching off the tips of your basil will keep your plants dense and bushy, encourage fresh growth, and prevent flowers from forming. Young leaves are more tender than older leaves, so pinch or clip your basil frequently through the

Pinching Flowers and Herbs

Months applicable: April, May, June, July, August

Tags: Best Practices, Herbs, Ornamental Plants, Techniques

Plant Asparagus Crowns

Asparagus crowns can be planted now. Dig a trench eight to twelve inches deep, mix in fertilizer at the bottom and cover with two inches of soil. Set the roots in the trench about 18 inches apart, and cover with two inches of soil. Gradually fill in the trench as the plants start to grow. Asparagus is a perennial vegetable that will produce for several years. It's best to wait until the second year to harvest to let a strong root system develop for long term production. For more information, read UC Davis' Growing Asparagus in the Garden.

Months applicable: January, February, March

Tags: Techniques, Vegetables

Plant Cool Season Vegetables again

Salad greens, carrots, beets, fennel, broccoli, and bok choy are just a few of the vegetables that you can plant now. The warming weather and longer days will help them mature quickly. By the time they’re done, it will be warm enough to plant summer vegetables like tomatoes and peppers. You can direct seed into the garden or get a head start by transplanting seedlings. Use our vegetable planting chart for a full list of suggestions.

Months applicable: February, March, April

Tags: Garden Basics, Vegetables

Plant Garlic & Shallots

The time to plant most garlic and shallots is mid-October through the end of November. Fast-growing Dutch Red shallots can mature in just 90 days, so can be planted again in late winter or early spring. Specialty growers guarantee disease-free stock and offer many more garlic varieties than you see at the grocery store, from beefy Chopaka Mountain to beautiful Rose de Lautrec.

Choose the largest cloves and leave the natural papery wrappers on them. Plant them in moist, well-drained soil in a sunny location with the pointy tips up, about one inch deep. Space cloves about four inches apart to leave room for large heads to develop.

More information: How to Grow Garlic | How to Grow Shallots

Months applicable: February, March, October, November

Tags: Vegetables

Plant Native Shrubs and Flowers

Native shrubs like manzanitas, silk tassel bush, and currants come into bloom and provide nourishment for wildlife at the height of winter. These carefree, water-wise shrubs look good throughout the year.

Winter is still a good time to plant native plants. It is not too late to scatter wildflower seeds like California poppy, mountain garland, baby blue eyes, globe or bird's eye gilia, clarkias, lupines and tidy tips. Make sure the seeds have good soil contact by walking or tamping on the seeded areas. Consider planting native bulbs like wild hyacinth, mariposa lily, harvest brodiaea or soap plant in areas that remain dry through the summer, perhaps at the feet of established shrubs.

If you've had California poppies before, they'll start popping up all around as a result of winter rains. If you're interested in brilliant orange spring color, you can still scatter seeds now. When choosing a spot to plant them, keep in mind that they re-seed themselves readily and they can smother nearby small plants.

Months applicable: January

Tags: Ornamental Plants, Trees & Shrubs, Waterwise Plants

Plant Propagation

You can plant seeds to grow new plants, but you can also create new plants by taking cuttings of stems, leaves or roots. This is called asexual propagation. It creates an exact clone of the parent, allowing you to preserve and multiply your favorites for your garden. Using sterilized clippers, snip a stem section just below a node (where leaves attach). Place it in the proper growing medium or water to root and prepare for planting. Whether you plant seeds—perhaps saved from your summer garden—or use cuttings from plants you love, plant propagation will save money and expand your plant collection.

More information:

• Plant Propagation for Home Gardeners
• Plant Propagation for Home Gardeners, Part 2

Months applicable: Any month

Tags: Fruits & Nuts, Herbs, House Plants, Ornamental Plants, Techniques

Planting Berries

Berries including blackberries, raspberries, blueberries, and some strawberries can be planted in the fall through early spring. When purchasing blackberries and raspberries, it is best to get plants that are certified disease-free from a nursery. Most berries prefer deep, well-drained, loamy soil with a slightly acidic pH (5.5-6.5). Bare-root plants can be planted in the fall, winter and early spring. Potted green plants can be planted any time they are available in the nursery. A northern sun exposure is best.

More information: Growing Berries

Months applicable: October

Tags: Fruits & Nuts

Planting Bulbs

Bulbs that bloom in the spring are planted into the ground in the fall. These include those that are technically corms, rhizomes, tubers, or tuberous roots in addition to true bulbs. Examples are babiana, crocus, daffodils, freesia, hyacinths, iris, ixia, sparaxis, and tulips. They can go into the ground in groups, into pots, or be tucked in amongst other plants. They need to be in a place that doesn’t stay wet because they will rot with too much water. It is important that the soil has good drainage. They flower best in full sun or filtered shade.

Be sure to plant them with the pointy side up because new growth will come from that point. A rule of thumb is to plant them twice as deep as the diameter of the bulb, but follow instructions for the specific flowers. Water them in at planting time.

More Information: Bulb Planting Schedule , Tips for Growing Bulbs

Months applicable: September, October, November

Tags: Container Gardening, Ornamental Plants

Planting Ornamentals

Spring is when thoughts turn to planting, yet fall is an excellent time to plant perennials. You can plant many trees, shrubs, and other long-lasting plants in the fall. This applies particularly well to California native plants. Putting them in now will give them a chance to start developing strong root systems with the winter rains before they are stressed by summer heat. Make sure to water new plantings regularly until they have established good root systems and can survive with less supplemental water.

Months applicable: September, October, November

Tags: Ornamental Plants, Trees & Shrubs

Planting Trees or Shrubs

You may be tempted to amend the soil when planting trees or shrubs, but it’s no longer recommended. If the soil in the hole is amended, it creates soil moisture differences that discourage the roots from growing into the native soil beyond the hole. For best results, dig a hole about twice as wide as the container. Rough up the sides to help the roots penetrate. Don’t loosen the soil in the bottom of the hole or the plant may settle too low. The goal is to keep the crown of the plant slightly above the surrounding soil. Then simply backfill with the native soil from the hole.

More information: Planting for Success

Months applicable: March, April, May, September, October, November

Tags: Best Practices, Techniques, Trees & Shrubs

Plants to Attract Butterflies

Butterfly populations fluctuate in response to climate and habitat conditions. Many have specific host plants on which they feed and breed. Some common plants for attracting butterflies are milkweed, lantana, buddleia, and zinnias. For an extensive list of relationships between specific butterflies and host plants, see Art Shapiro's Butterfly Site at UC Davis.

Months applicable: March, April, May, June

Tags: Beneficial Insects, Ornamental Plants

Plum Bud Gall Mite

Plum bud gall mites are tiny and you won’t be able to see them without magnification. Their feeding causes the galls to form on the tree. These galls are made up of different chambers and these chambers can be filled with a large population of mites. The mites are primarily dispersed by wind but can be spread by insects, birds, and infected budwood. Heavy infestation can weaken trees and in some cases cause the death of the tree. If you suspect that your tree is affected by these mites, you should avoid moving budwood off your property to keep from spreading the pest. Because they are a new pest, options for managing them are still being developed. See Plum Bud Gall Mite for further information.

Months applicable: February

Tags: Fruits & Nuts, IPM, Invertebrates

Poinsettias

Poinsettias are tropical plants, so they'll do best in a warm, sunny place in your house. The soil can easily dry out and become hydrophobic, so make sure to check the soil moisture regularly. There’s really no need to fuss over them if you’re only keeping them for a few weeks of holiday color. If you want them to bloom again next year in time for the holidays, UC has Poinsettia Care Tips that describe what to do; just be aware that it is a little tricky.

Did you know that the red parts are actually bracts (modified leaves) and that the true flowers are the little yellow parts in the centers? You can also plant them outdoors with protection from frost. They have been seen growing as tall as eight feet in San Jose, and taller in their native Mexico.

Months applicable: January, December

Tags: Ornamental Plants

Poison Oak

Poison oak is a California native plant that provides shelter and food for many native birds and other creatures. The downside is that at least 75% of us develop allergic contact dermatitis to the plant. Unwanted poison oak can be pulled or dug up by allergy-resistant friends, remove plants in early spring or late fall when the soil is moist and it is easier to dislodge rootstocks.

A complete list of management options, including herbicide control, is contained in the UC Pest Note on Poison Oak. Under no circumstances should poison oak be burned.

Months applicable: February, March, April, November

Tags: Disease, IPM, Trees & Shrubs

Poisonous Plants List

As we approach the holidays, there are a lot of questions on poisonous plants. Fortunately, many of these plants have a very bitter taste that limits the amount of the plant eaten.

Poinsettia and mistletoe should be kept away from curious children, but the list includes other flowers and plants such as azaleas, calla lily, carnation, daffodil, foxglove, hydrangeas, iris, lantana, narcissus, poppy, sweet pea and tulips.

Different parts of the plant may be toxic. Consult the UC Poison Plant web page for detailed information.

Months applicable: November, December

Tags: Best Practices, Container Gardening, Ornamental Plants

Potting Mix vs Planting Mix

Is there a difference between potting mix, potting soil, and planting mix? The best advice is to read the label. The terms for bagged mixes aren’t regulated, so they can vary by manufacturer. What’s important to know is that not all bagged mixes can be used in pots. Some are meant to be used as garden fill, amendment, or mulch, so they won’t provide the right water retention, drainage, or nutrients for container gardening.

For more information: Bagged Potting Mixes

Months applicable: March, April, May, November

Tags: Garden Basics, Ornamental Plants, Soil, Vegetables

Powdery Mildew

Have you ever seen a squash or melon without white powder on the leaves in the fall? This fungal disease is called powdery mildew. It affects several vegetable, fruit, and ornamental plants; yet it seems almost inevitable on members of the Cucurbitaceae family which includes cucumbers, gourds, melons, squashes, and pumpkins.

Powdery mildew likes warm days and cool nights. Unlike most other fungi, it does not need moisture to thrive. Early symptoms include yellow chlorotic spots on the leaves. The presence of the fungus becomes obvious as it starts to produce spores that look like white powder on leaves. Eventually, the leaves will turn brown and dry.

The best defense is to plant varieties that are resistant to powdery mildew. Also helpful is planting in full sun with good air circulation through the plants. Washing off the leaves, preferably in the morning, can buy some time. Powdery mildew generally affects the older leaves first, and you can remove these when they are too covered to be able to photosynthesize. Fungicides can help but you want to be careful about using them around something you are going to eat. At some point, the plant may decline so much that it needs to be removed.

Months applicable: August, September, October

Tags: Disease, IPM

Preserving Fruits and Vegetables

Interested in how to preserve fruits and vegetables? UC Food Safety has lots of information including "Safe Handling of Fruits and Vegetables", "Safe Methods of Canning Vegetables", "Chart on Storing Fresh Fruits and Vegetables", and more. Visit their web page UC Home Preservation and Storage Publications for more details.

Months applicable: August, September

Tags: Best Practices, Fruits & Nuts

Prevent Fruit Tree Sun Burn

Months applicable: April, May, June, July

Tags: Best Practices, Fruits & Nuts

Protect Native Bees

You probably see non-native honeybees in your garden, but do you know there are over 1600 species of native bees in California? These bees don’t make honey, don’t live in hives (most live right in the ground), and are much less likely to sting since they have no colonies to defend. Research shows some species pollinate crops twice as effectively as honeybees, plus they’re best suited to pollinate native plants. But like honeybees, they’re threatened by pesticides and loss of habitat. Help preserve these species by growing a variety of plants that flower at different times of the year and by keeping areas of open ground in your yard.

More information: Native Bees and Their Favorite Plants

Native Bee images, clockwise from top left: Leafcutter bee (Jim McCulloch), carpenter bee (Kathy Keatley Garvey), long-horned bee (Kathy Keatley Garvey), sweat bee (Missouri Department of Conservation Staff)

Months applicable: March, April, May, June, July, August

Tags: Best Practices

Protecting Birds and Crops

This is nesting season for many birds, so be sure to check for active nests before pruning trees. Birds are good for natural pest control, as they eat many insects, and they improve your garden’s biodiversity. You can also encourage birds in your yard by providing food and water for them. Just be sure the water stays fresh and clean.

To protect fruit and nut trees from marauding birds, PVC structures covered with netting can save your crop. If netting is placed directly on the tree, birds will still be able to reach much of the fruit. There's more information in the UC Pest Note on Birds on Tree Fruits and Vines.

Months applicable: April

Tags: Fruits & Nuts, IPM, Vertebrates

Protecting California

What is an invasive pest?

Months applicable: Any month

Tags: Best Practices, IPM

Protecting Fruit

If you don't eat your fruit the minute before it's ripe, birds or squirrels will. Once you see signs of damage, either pick the fruit, or find a way to protect it. For example using netting or paper bags. Pick up any fallen fruit as so not to attract rats or other less visible pathogens.

Months applicable: July

Tags: Best Practices, Fruits & Nuts, IPM, Vertebrates

Prune Apple Trees

Once your apple tree loses its leaves, it's time to think about pruning. Apple trees produce fruit terminally on spurs located on wood 2 yrs. to 8 yrs. old. Weak and unproductive branches should be thinned out to allow the sunlight into the tree for good spur development. Older spurs can be rejuvenated by cutting back, especially following a light crop year. Tree height is maintained by cutting back upper branches to shorter laterals. Excessive pruning of a bearing tree can negatively affect its vigor and fruit. Consult our Fruit Tree Pruning page for more information.

Months applicable: January, February, December

Tags: Fruits & Nuts

Prune Apricot and Cherry Trees

August is the best time to prune apricot and cherry trees in our area. By pruning at least six weeks before the first fall rains, you reduce the chance of Eutypa dieback. The disease is caused by a fungal parasite caused by airborne spores that enter fresh pruning wounds. Cankers develop around an infected wound and eventually can kill a tree if not managed.

Months applicable: July, August

Tags: Fruits & Nuts, Techniques

Prune Blackberries

Little or no pruning is required during the first year after planting. Blackberries should be pruned as soon as the harvest is completed. All wood that has produced the current crop should be removed. The canes should be trellised immediately after pruning. Put up only the larger canes and prune the small ones. Generally, no more than 9 canes should be put up on the trellis. A fan-like arrangement is the best way to trellis the vines. Tipping (removing the end of the canes) forces out the laterals on which fruits will be borne the following season. Consult our Berries page for more information.

Months applicable: December

Tags: Best Practices, Fruits & Nuts, Techniques

Pruning Azaleas and Rhododendrons

Azaleas and rhododendrons can be pruned as soon as they finish flowering. This is also a good time to fertilize them. Choose an acid-forming fertilizer blended for these particular plants, and be sure to follow the label directions for amounts. Learn more by visiting the Azalea and Rhododendron society websites.

Months applicable: April, May

Tags: Ornamental Plants, Trees & Shrubs

Pruning Bougainvillea

You can prune at any time to shape or direct growth. If it is growing on a wall, cut back long stems to keep producing flowering wood. Hard pruning to renew the plant should be done in the spring after the last frost.

Months applicable: April, Any month

Tags: Ornamental Plants

Pruning California Natives

If your landscape includes California native plants, you may wonder if you should prune them. It depends. Some don’t respond well to shaping or shearing to control size. But they do like careful pruning at the proper time, which is when they are dormant. That could be either summer or mid-winter. Natives that do well with winter trimming include California buckeye (Aesculus californica), honeysuckle (Lonicera hispidula), and salvia species. California fuchsia (Epilobium canum) and lilac verbena (Verbena lilacina) can be cut almost to the ground. But wait until summer for grasses and broadleaf evergreen shrubs and trees.

More information: How to Prune California Native Plants

Months applicable: January, February

Tags: Ornamental Plants

Pruning Camellias

April and May are the best time to prune camellia. Camellia should be pruned just after flowering and before new vegetative growth gets going. If you prune later in the season, you risk damaging next years blossoms.

Months applicable: April, May

Tags: Best Practices, Ornamental Plants, Trees & Shrubs

Pruning Dead Branches

As dormant trees and shrubs begin to leaf out, it will be fairly easy to see which parts are dead. Prune back to live wood to avoid diseases and keep your garden healthy. Swelling buds and a thin green layer just under the bark are signs that the wood is alive. Find tips on pruning at the UC Home Orchard website. If larger trees need pruning, hire a professional. The International Society of Arboriculture (ISA) has a searchable list of certified arborists.

Months applicable: March, April

Tags: Techniques

Pruning Fuchsias

The time to prune fuchsias is early spring, after the chance of frost is past. If there is frost damage prune it out and take off some of last summer's growth. Leave at least two or three healthy leaf buds on each branch. Fuchsias have a tendency to get leggy. Frequently pinch the tips of the branches during the spring and summer to force side growth, making the fuchsia bushier. Pick off flowers as they fade.

More information: UC IPM list of common pests and disorders of fuchsias.

Months applicable: February, March, April

Tags: Ornamental Plants, Techniques

Pruning Hydrangeas

For better-looking hydrangeas, prune out the spent blossoms. Hydrangeas are fast growing and need pruning to control size and shape. Cut out the older stems that have flowered, leaving the ones that have not flowered. For the biggest flower clusters, reduce the number of stems. For lots of medium size flowers, keep more stems.

Months applicable: August

Tags: Best Practices, Ornamental Plants, Trees & Shrubs

Pruning Large Limbs

When cutting large limbs, take special care to prevent ripping of the limbs and trunk since a clean cut heals faster. Use a three-cut method for branches larger than 1" diameter. Step 1: make a cut halfway through the underside of the branch, a little past where you want the final cut. Step 2: move the saw to the top of the branch, a little further out on the branch, and cut the branch off. Step 3: make the final pruning cut close to the connecting branch or trunk, just outside the bark collar. For more helpful information view UCCE Tips for Pruning Citrus.

Months applicable: February, Any month

Tags: Best Practices, Techniques

Pruning Tools Maintenance

Remember to keep your pruners and loppers clean and sharp. Read our tool care tips webpage for advice about cleaning, sharpening, and sterilizing your tools.

Months applicable: January, February, December, Any month

Tags: Best Practices

Raised Beds

• Gardening in Raised Beds (Page 7)
• Raised Beds in Vegetable Gardening Basics
• Quick and Easy Raised Bed Design

Months applicable: March, April

Tags: Best Practices, Techniques

Rat Management

Have you found a hollowed-out orange or other sour fruit like Meyer lemons with no skins, tomatoes with bite marks, fruit with holes gnawed in them, or grape skins or cherry tomato skins scattered around? It is the work of a roof rat.

Rats show up when your citrus, tomato, or fruit first starts to ripen. Rats are agile climbers and usually live and nest in shrubs, trees, and dense ground cover like ivy. One management strategy is to prevent access to the tree by cutting branches away from fences or other trees, leaving a gap of at least 2–3 feet, good sanitation is required. Garbage and garden debris should be eliminated. Use tight-fitting lids on garbage cans. Thin out dense vegetation to make the habitat less desirable. Mow ivy once a year to the ground. Climbing ivies on fences or buildings should be removed.

Per the UC pest note (linked below), trapping is the safest and easiest method for controlling rats. Read the pest note for other management strategies as well.

More information: Rat Management

Months applicable: January, February, March, April, July, August, September, Any month

Tags: Best Practices, Disease, Fruits & Nuts, IPM, Vegetables

Recycle Holiday Plants

If you have a Christmas tree to recycle, please follow the procedure for your local community program so that the trees can be recycled into compost or materials. Insects and diseases which may be on the cut trees could escape and spread if the trees were used as mulch in homeowners' yards.

Other popular holiday plants such as poinsettias, azaleas, or cyclamen can also be recycled. Remove the foil wrapping off the containers (for better drainage) and put the outdoor plants somewhere sheltered until you can plant them. The heated air in your home will dry out both these outdoor plants as well as your indoor plants. You may want to check those indoor plants too.

Months applicable: January

Tags: Best Practices

Remove Thatch in Lawns

If you have a lawn, April is the time to remove thatch. Thatch is a layer of dead and living stems, roots, stolons, and rhizomes, between the green blades of grass and the soil surface. If thatch becomes too thick, it can keep water, air, and nutrients from reaching the soil and roots. Thatch can be removed with a thatch rake to improve the health of the grass. The UC Guide to Healthy Lawns has more information.

If you are tired of mowing and raking and watering that lawn, you may want to check on the Santa Clara Valley Water District's Landscape Rebate Program. Even if the funding is used up for the year, you can still replace your lawn to conserve water, time, and energy. But don't start by digging it up. Instead, sheet mulch the area. Then you can add drought-resistant native plants or ground cover, such as yarrow, thyme, sage, creeping manzanita or ceanothus.

Months applicable: April, October

Tags: Lawns, Techniques

Reusing Soil in Containers

When the plants are done in the containers, you can refresh the container soil without throwing it away. Start by loosening the soil and removing the plant parts. Then, add additional potting mix and some compost. The fresh material will add nutrients and organic matter for the next round of planting. Do not reuse the container soil if there have been problems with disease, insects, or weeds. Pathogens, insect eggs, and weed seeds can remain in the soil even after a plant is removed.

More information: Gardeners can reuse, recycle last year's potting soil, Oklahoma State University Extension

Months applicable: November

Tags: Soil

Root Knot Nematodes

Root knot nematodes usually cause distinctive swellings, called galls, on the roots of affected plants. They can infest a wide variety of plants and easily spread via soil left on tools or shoes. Infested plants may not die but may be sickly or less productive. When you pull out your annual plants, inspect the roots, especially if they didn’t do well. Avoid spreading root knot nematodes by cleaning tools thoroughly. Consider letting an infested bed lie fallow for a season, or plant a cover crop next summer of French marigolds, which help suppress some nematodes.

More information: Nematodes Pest Note

Months applicable: September, October, Any month

Tags: Fruits & Nuts, IPM, Ornamental Plants, Trees & Shrubs, Vegetables

Rose Care

Months applicable: May, June, July, August

Tags: Abiotic Disorders, Best Practices, Disease, IPM, Ornamental Plants, Techniques, Trees & Shrubs

Save Water and Make Your Plants Happier

After your vegetable garden is well established, it's better to water thoroughly once a week rather than giving it a light watering every day. Doing that will encourage a deeper root system which will help the plants tolerate dry weather better. This is also true for fruit trees. For more information visit UC Pest Note on Watering Fruit and Nut Tress.

Months applicable: July

Tags: Best Practices, Vegetables, Waterwise Tips

Save the Worms

Worms aerate the soil with their tunneling, break down organic material such as fallen leaves and make the nutrients available to plants, and they excrete nice rich fertilizer in the process. They help create a sustainable system in your garden and do a lot of your garden chores for you. If you see them on the sidewalk during heavy rains, rescue them and take them to a safe place in your yard.

Months applicable: January, February

Tags: Best Practices

Seed Viability

Seed packets have a “packed for” date on the back. Yet seeds can still be viable for years beyond that date if stored correctly. Ideal storage conditions are cool and dry. The older the seeds are, the lower the germination rate will be. So plant more of the older seeds than the number of plants you ultimately want. You can do a germination test by putting seeds on a damp paper towel and enclosing them in plastic to keep them uniformly moist. Do this right before planting time so you can transplant the ones that successfully germinate. Or you can take your chances and just plant them directly and see what comes up. If you are saving your own seeds, make sure to choose seeds from the healthiest plants.

Whenever it's hard to find flower seedlings, if you have some old flower seed packets, you can scatter the seeds randomly in a section of your yard and enjoy whatever flowers.

Months applicable: January, February, March, April, May, August, September, October

Tags: Ornamental Plants, Techniques, Vegetables

Selecting Seeds

While curled up inside the warm, dry house poring through seed catalogs, how do you decide among all the delightful descriptions? First, be clear on the purpose of your garden. Are you trying to grow exotic food? Do you want to attract native butterflies? Are you interested in flowers you can cut and bring inside? Next, think about the conditions of your site. Is it warm and sunny or is there a lot of shade? Do you have heavy clay soil? Choosing seeds that do well in your area makes for healthier plants with less work. At this point, you have the parameters within which to choose what tickles your fancy. If you would like to save seeds in the future, then choose open-pollinated seeds, including heirlooms. Heirlooms are open-pollinated seeds that have been around for multiple generations. Otherwise, you can plant hybrids that have the best traits of their parent plants but will not reproduce true to type from saved seeds. Follow planting directions on the packet for the best results.

Months applicable: January, February, March, May, June, July, August, October

Tags: Best Practices, Garden Basics, Ornamental Plants, Techniques, Vegetables

Sheet Mulching - "Lose the Lawn"

An easy and environmentally friendly way to "lose the lawn" is to smother the grass and mulch at the same time. Place cardboard or several layers of newspaper over the area, overlapping by eight inches to keep weeds from finding openings. Wet the cardboard or newspaper, then cover it with 4-6 inches of compost, plant trimmings, or other mulch. Having wood chips on top will give it a neat appearance. The materials will gradually break down and improve the soil over time. New plants can be installed by cutting an X in the cardboard or newspaper and placing the plants right through the mulch. UC Davis Arboretum Horticulturist Stacey Parker's website shows you how it's done.

Months applicable: March

Tags: Lawns, Soil, Techniques

Should You Prep Soil for Planting?

It’s tempting to grab a shovel and turn over all the soil in your garden as you prepare for summer planting. But should you? Increasingly, science is saying “no.” Every time you dig into the soil, you’re disturbing a very intricate, living web of organisms, bacteria, and fungi that your plants need to thrive. In contrast, a “No-Till” approach minimizes soil disturbances and keeps organic material like leaves, compost and coarsely chopped plants on the ground’s surface to slowly decompose. By keeping it moist and protected from beating sun and pounding rain, this organic material allows the soil to stay crumbly and ideal for planting.

More information: No-Till for Home Gardeners

Months applicable: March, April, May, October, November

Tags: Best Practices, Garden Basics

Shovel Pruning

Months applicable: March, September

Tags: Best Practices, Ornamental Plants, Techniques, Trees & Shrubs

Shrubs

Months applicable: October

Tags: Best Practices

Vinegar as Weed Control

Vinegar can work as a weed killer, but its effectiveness is limited. Household white vinegar (5% acetic acid) is too weak to kill anything other than tiny seedlings. Stronger horticultural vinegars with 20% acetic acid provide better weed control but typically only for annual, not perennial, weeds. And the higher concentration can be dangerous—including skin burns and eye injury—if not handled carefully. For comprehensive guidance on weed management in landscapes, refer to the University of California’s Weed Management in Landscapes recommendations.

Months applicable: Any month

Tags: Techniques, Weeds

Water Budgeting

Months applicable: May, June, July, August

Tags: Fruits & Nuts, Irrigation, Ornamental Plants, Trees & Shrubs, Vegetables, Waterwise Plants, Waterwise Tips

Water the Roots, Not the Plants

It's tempting to get the hose out and spray your dry, thirsty plants, but you don't want to waste water. Keep their feet nice and cool, but resist the urge to squirt the leaves unless they need a cleaning (for dust or white fly for instance).

It's a common belief that daytime water on the leaves will burn them. While it's possible, according to scientists—for hairy leafed plants where water droplets are held above the leaf surface—but not very likely. It's more the water will simply evaporate and not do your plants much good and could encourage fungal pathogens if wet overnight.

Months applicable: June, July, August

Tags: Irrigation, Waterwise Tips

Watering Hydrophobic Soil

Just as a dry sponge repels water, overly dry soil can do the same thing. This dried out soil is called hydrophobic. Hydrophobic soil can waste a lot of water as water drains away from the plant's root zone.

In pots: learn more about how to re-wet very dry soil on our Watering Hydrophobic Soil page. In the yard: setting sprinklers to run for 5 minutes, waiting for the water to soak in, and then running for a longer time can prevent water loss due to hydrophobic soil.

Months applicable: May, June, July, August

Tags: Irrigation, Techniques, Waterwise Tips

Watering Tomatoes

If you haven't already, it's time to cut back on watering tomatoes. Tomatoes have far more flavor when the ripening fruit is deprived of water. Don't forget to remove competing weeds from around the garden.

Months applicable: July

Tags: Best Practices

Watering Trees

The amount of water trees need in the summer depends in large part on the age of the tree. Newly planted trees with shallow roots may need weekly water. Trees that are a few years old and fairly well established may need monthly watering. Mature trees with extensive root systems may not need any supplemental water. These are just VERY general guidelines. It is essential to know the water requirements of the plants. You can determine these by researching cultural needs or knowing their native habitats, the soil type and how well it retains water, and the micro-climate in which the tree is located, e.g., shaded, windy, dry. The UC WUCOLS database has information on the water needs of over 3,500 plants used in California landscapes. Always water slowly and deeply to penetrate down to the roots. Use a soaker or drip hose around the tree at the drip line and let it slowly drip for 2 to 3 hours. Don't let lawn sprinklers hit tree trunks as this may cause crown rot and damage the tree.

Months applicable: July, August, September

Tags: Irrigation, Trees & Shrubs

Weed Management

While some weeds are edible (purslane, nettles, dandelions, miner's lettuce), many are a nuisance and compete with your chosen plants for water and nutrients.

Months applicable: January, February, March, Any month

Tags: Best Practices, IPM, Weeds

Weed Spotlight - Bindweed

Have you seen a pretty, morning glory-like flower on a vine that winds through any plant within reach? Field bindweed is one of the most challenging weeds to control because its roots can reach depths of 20 feet or more and it readily re-grows from root fragments as short as 2 inches. The only chance of controlling this invasive weed is to stay right on top of it and remove it as soon as you see any of it peeking up out of the ground. Every time it starts growing above ground and photosynthesizing, it is storing energy in the roots. This allows it to put out new shoots. It produces many seeds which remain viable for years. Making things even worse, it’s drought tolerant. Controlling it isn’t easy, but the UC pest note below discusses options. Chemicals aren’t needed if you’re persistent in removing new growth to prevent seed production and limit the plant’s ability to store new energy in the roots.

For more information: Field Bindweed Pest Notes

Months applicable: March, April, May, June, July, August, September, Any month

Tags: Weeds

Weed Spotlight - Common Fumitory

Have you noticed this feathery weed popping up here and there in your yard? It’s called fumitory, Fumaria spp., for its smoke-like appearance. This delicate annual plant forms pretty, little, pinkish-white flowers with maroon lips. But beware, those flowers make many seeds that can sprout in the tiniest cracks. While the plants are easy to pull, the seeds can be quite persistent. The little seedlings can hide under larger plants, so check carefully if you want to head off an infestation.

Months applicable: Any month

Tags: Weeds

Weed Spotlight - Filaree

Months applicable: April, May, June, Any month

Tags: Best Practices, Weeds

Weed Spotlight - Mallows

Winter rains bring cheerful-looking plants whose heart-shaped leaves beguile gardeners into thinking they are simple weeds that are easy to pull. But beware. These plants are mallows (also called cheeseweeds) and underneath the innocent leaves of mature plants lie deep, thick, woody taproots that are hard to remove with garden tools. They even interfere with heavy farming machinery! Remove young plants with four or fewer true leaves right away. You can also add 3 inches of organic mulch to suppress seedlings.

For more information: Managing Mellows

Months applicable: Any month

Tags: Weeds

Weed Spotlight - Spotted Spurge

Months applicable: March, April, May, June, Any month

Tags: Weeds

Wet Soil

The clay soils which dominate our area are particularly susceptible to compaction, especially when they have received a lot of rain. These soils are characterized by small mineral particles. Hence squeezing out the air spaces makes it more difficult for plant roots and soil organisms to get the oxygen they need to flourish. Try to avoid walking on or using heavy equipment on soil that is wet. Digging in wet soil can also destroy the structure, breaking up useful soil aggregates and earthworm tunnels. Try to wait until the soil is moist, not wet or dry, for easiest tillage. If you must walk or stand on the soil, use a board to distribute your weight over a broader area. Mulch can also create a bit of a cushion and help minimize compaction.

Months applicable: February, March, December

Tags: Soil

When to Start Summer Vegetables from Seed

If you start your seedlings too soon, they can get leggy and overgrown before it’s time to plant them. Tomatoes reach transplant size in 6 weeks, peppers take 8–10 weeks, and cucumbers take just 4 weeks. Plan when you want to transplant into the garden, then calculate backward to figure out when to start seeds. Our vegetable planting chart recommends transplanting tomatoes in May, so start seeds 6–8 weeks before, in March to early April. The hottest varieties of peppers need a long growing season for the pods to ripen. Start peppers earlier, mid-February to mid-March. Wait until May to start heat lovers like cucumbers and melons.

More Information: Growing Transplants from Seed

Months applicable: February, March, April

Tags: Best Practices, Garden Basics, Vegetables

White Butterflies and Green Caterpillars

Have you seen these small yellowish-white butterflies fluttering around? Cabbage white butterflies feed on many flowers, but for laying their eggs. They favor the cabbage family, such as broccoli, cauliflower, and mustard. The velvety green caterpillars, also called imported cabbageworms, feed on the leaves after hatching. While mature plants tolerate a few holes munched in their leaves, young seedlings don't have foliage to spare. Cultural controls include handpicking the caterpillars, brushing the eggs off the undersides of leaves, and using row covers to protect the seedlings. UC lists additional options in the link below.

More information: Managing Imported Cabbageworms

Months applicable: March, April, May, June, July, August, September, October, November

Tags: Invertebrates, Vegetables

White Mold on Lettuce and Brussels Sprouts

White mold is a distinctive disease that most often affects stems and foliage at the base of cole crops^* and lettuce plants. Affected tissue develops a soft, watery rot and white, cottony mycelium forms on the surface. Plants may wilt if stems are girdled by the decay. As affected tissue dries up, it turns yellow to white, and hard black sclerotia form on the surface or inside the dead stems. Get more information in the UC Pest Note on White Mold.

^* Cole crops include broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, and kohlrabi

Months applicable: November, December

Tags: Disease, IPM, Vegetables

Whiteflies

Whiteflies are tiny, sap-sucking insects that may become abundant in vegetable and ornamental plantings, especially during warm weather. They excrete sticky honeydew and cause yellowing or death of leaves. Outbreaks often occur when the natural biological control is disrupted. Management is difficult once populations are high.

Whiteflies use their piercing, needlelike mouthparts to suck sap from phloem, the food-conducting tissues in plant stems and leaves. Large populations can cause leaves to turn yellow, appear dry, or fall off plants. Like aphids, whiteflies excrete a sugary liquid called honeydew, so leaves may be sticky or covered with black sooty mold that grows on honeydew (See UC Pest Note on Sooty Mold). The honeydew attracts ants, which interfere with the activities of natural enemies that may control whiteflies and other pests.

Management of heavy whitefly infestations is difficult. The best strategy is to prevent problems from developing in your garden or landscape. In many situations, natural enemies will provide adequate control of whiteflies; outbreaks often occur when natural enemies are disrupted by insecticide applications, dusty conditions, or interference by ants. Avoid or remove plants that repeatedly host high populations of whiteflies.

In gardens, whitefly populations in the early stages of population development can be held down by a vigilant program of removing infested leaves or hosing down with water sprays. Reflective mulches can repel whiteflies from vegetable gardens, and yellow sticky traps can be used to monitor or, at high levels, reduce whitefly numbers. If you choose to use insecticides, insecticidal soaps or oils such as neem oil may reduce but not eliminate populations. Systemic insecticides may be more effective but can have negative impacts on beneficial insects and pollinators.

For more information see UC Pest Note on Whiteflies.

Months applicable: June, July, August, September

Tags: IPM, Invertebrates, Vertebrates

Why You Should Test Your Soil

Before adding fertilizer or soil amendments to your garden, first find out what your soil really needs by conducting a soil test. Knowing your soil’s pH value is important in determining which plants will thrive or struggle in your soil. Understanding the levels of nitrogen, phosphorous, and potassium in your soil will tell you which nutrients are abundant and which are lacking. Don’t overfertilize – excess nutrients can pollute local waterways. Commercial soil testing labs provide the most thorough results, but several home kits can give you a good baseline. Test soon and be ready for spring planting.

Months applicable: January, February, March

Tags: Soil

Wildfire Effects

Months applicable: September, October

Tags: Best Practices

Will Pine Needles Acidify My Soil?

Months applicable: Any month

Tags: Soil

Winter Irrigation

Depending on the fall weather and rain frequency, you will likely set your sprinklers to water less frequently or even turn them off for a while. It's still important to check outdoor plants to ensure they have enough water. While they need less water when it's cool, it's important to make sure they don't dry out. If you have a lawn and rains haven't come, irrigate the lawn once or twice this month.

If it has been raining, the soil may be saturated, so be careful if you have to walk on it to not compact it. Also, if the soil is waterlogged, vital space for air needed for plants and worms, and excess water can drown beneficial soil organisms and contribute to rotting roots.

Months applicable: January, February, December

Tags: Irrigation, Lawns, Ornamental Plants, Vegetables

Winter Soil Health

Areas of the garden that are not actively planted still need protection to support soil life and prevent soil erosion. Cover crops are one option. Their roots break up the soil, and if they are legumes, like fava beans, they add essential nitrogen. Mulches hold in moisture, moderate soil temperature, and help prevent weeds from germinating. Unlike rocks and synthetic mulches, organic mulches like leaves, wood chips, or straw also slowly break down, beneficial soil organisms, and add nutrients to the soil. A top layer of an inch or two of compost will slowly work down into the soil, amending it with organic matter. Manure from herbivores can also be spread over the top of the soil. Even fresh manure, which could burn plants if applied directly, can be used over a bare area to decompose in place and be ready for the next planting season.

Months applicable: October, November

Tags: Best Practices, Soil, Techniques

Winter Squash Harvesting

Winter squash is ready to pick when the stem begins to shrivel. Press the rind with your fingernail, it should resist denting. Pick before the first hard frost and cure by letting it lie in the sun for at least 3 days, turning it each day. Store in a cool, dry place. It will keep for up to 5 months.

Months applicable: September

Tags: Vegetables

Winter Vegetables

It's good to plant winter vegetables so they have time to get established before cool winter weather arrives and the day length wanes. We recommend planting most cool season vegetables in early fall. But you might still have luck transplanting leafy greens such as lettuce, arugula, spinach, and kale, and fast growers like radishes and cilantro even later. In our vegetable planting chart, check the months when planting might work. Remember that vegetables need at least 6 hours of sun for strong, healthy growth.

Months applicable: September, October, November

Tags: Best Practices, Vegetables

Worm Composting

Worm composting, also called vermiculture or vermicomposting, is a convenient way to decompose kitchen waste and provide nutrient-rich soil amendments for your vegetable garden.

The Santa Clara County Home Composting Education Program offers:

• Worm workshop classes
• Sources for worms

Months applicable: February, June, September

Tags: Soil

Yellow Leaves on Citrus Trees

While there are several possible causes for yellow citrus leaves, the most likely one in winter/early spring is that citrus roots do not absorb nitrogen efficiently from cold, wet soils. There may be adequate nitrogen in the soil, but the roots aren’t able to take it up. However, if the tree doesn’t green up when the weather warms, give it some nitrogen fertilizer, up to 1 lb of N per year for a mature, full-size tree. Dwarf trees or ones in containers require less fertilizer, 1/2 lb of N or less. Do not overfertilize since that may cause other problems.

More information: Growing Great Citrus

 

Months applicable: January, February, March, April

Tags: Techniques, Trees & Shrubs

Yellowing Leaves on Gardenias

Chlorosis is usually caused by a lack of iron in the soil. With a mild case, the veins remain green and as it becomes more severe will turn completely yellow. Treat the soil with iron chelate according the package directions.

Months applicable: September

Tags: Abiotic Disorders, Ornamental Plants, Trees & Shrubs

Yellowjackets and Wasps

These insects can be solitary or live in group nests above and below ground. Yellowjackets can be aggressive when defending their nests. Since they nest in ground holes or inside walls and ceilings, you might encounter them on a hike or in your home. Avoid the area when possible. Paper wasps on the other hand, are relatively unaggressive, but they can be a problem when they nest in a trafficked location.

When eating outdoors, keep foods well covered. One strategy is to put out bait such as a piece of meat or an opened soda can some distance from the table before setting out the human food. Or, use a lure trap around the area you want to protect. Trapping the queens in the spring and workers during the summer can reduce local populations. See the UC Pest Note on Yellowjackets and Other Social Wasps for more information.

Months applicable: August

Tags: IPM, Invertebrates

Young Fruit Trees

If you have young fruit trees, particularly ones you just planted during bare root season, you want to protect them while they’re still delicate. Water them regularly while they are establishing their root system. Put mulch around the root area to hold in moisture, moderate the soil temperature, and help keep weeds from sprouting and competing for water and nutrients. Consider painting the trunk with white latex paint, diluted 50% with water. This will reflect the sun and help prevent sunburn. Sunburn is a problem because the bark can crack, allowing pests and diseases to enter the wood more easily. Once the tree is larger and has a full canopy, the leaves will normally provide sufficient protection.

More information: Video: Getting Fruit Trees off to a Good Start (88 min)

Months applicable: April, May

Tags: Fruits & Nuts

Spotted Wing Drosophila

Unfortunately, the Spotted Wing Drosophila is infesting local cherry, berry, and some other fruits. Look for holes in the fruit. Once the eggs hatch, maggots develop and feed inside the fruit, causing the flesh of the fruit to turn brown and soft. Dispose of infested fruit. Information on identification and control can be found in the UC Pest Note on Spotted Wing Drosophila.

Months applicable: May, June

Tags: Disease, IPM

Squash

Summer squashes are meant to be picked and eaten when they are small and tender. These include zucchini, crookneck, chayote, patty pan, and papaya pear squash. Winter squash is grown at the same time as summer squash. What makes it different is that it develops a harder rind that allows it to be stored long term to be used throughout the winter. It can also remain on the vine longer before harvesting. Some examples are butternut squash, pumpkins, and Tahitian squash. Squash plants should be in the ground by now and may already be producing fruit. Continue to water and fertilize them throughout the season and control weeds to ensure maximum production. If squash grows a few inches and starts to wither, it is probably not getting pollinated; you can manually transfer pollen from the male flowers (on stalks) to the female flowers (on developing fruit). An overabundance can be prepared for freezing or shared, or plants can be pulled out early to make room for the next season’s planting.

More Information: Summer Squash, Winter Squash

Months applicable: July, August

Tags: Best Practices, Vegetables

Squash Bugs

Squash bugs are about ½ long, brownish yellow and flattened like a stink bug. Zucchini is one of their favorite plants. Leaves will blacken and drop as they dry. They can be difficult to control. Placing row cover over young plants helps prevent infestation. Remove nearby vegetation where the bugs can over winter. More information can be read at UC Pest Note on Squash Bug.

Months applicable: July

Tags: Best Practices, IPM, Invertebrates, Vegetables

Squirrel Control

Squirrels are a common nuisance across Santa Clara County. They dig in pots, gnaw bark from plants, eat fruit and flower blossoms, and dig holes in yards. They are active during the day. Tree squirrels are distinguished from ground squirrels by their long bushy tails, lack of markings, and quick escapes up the nearest tree. They can be difficult to manage due to their persistence. Refer to the linked pest notes for options. A UC blog posting provides details about hunting and trapping regulations.

For more information: Pest Note on Tree Squirrels and Pest Note on Ground Squirrels.

Months applicable: May, June, July, August, Any month

Tags: Fruits & Nuts, IPM, Vegetables, Vertebrates

Stake Your Brassicas

Your Brussels sprouts and other brassicas may collapse with the weight of the rain. Tying them to a three-foot stake will maximize your chances for a better crop. If you're noticing yellow flowers on your broccoli already, the cold-then-warm temperatures have caused them to bolt; you can try new plants or start thinking ahead to your warm weather garden.

Months applicable: January

Tags: Techniques, Vegetables

Stink Bugs

Stink bug's eggs are white in barrel-shaped cylinders with concentric circles ending in a bull’s eye. You might find them on the underside of leaves or in plain sight on fruits and vegetables in your garden. Soon they will hatch, shapeshifting in appearance five times before becoming shield-shaped adults either in brown or green color. Called stink bugs because they excrete a smelly fluid when disturbed. These insects feed on a variety of fruits, nuts, and vegetables such as tomatoes, squash, and beans, leaving blemishes and dark pinpricks in their wake. The best way to control them is to handpick eggs and bugs off plants and get rid of weeds where they may live. It’s not helpful to use insecticides because by the time you notice damage, the stink bugs will likely be gone already.

More information: UC Pest Note on Stink Bugs

Months applicable: July, August

Tags: IPM, Invertebrates

Stinkhorn Mushroom

You might find stinkhorn mushrooms growing out of a lawn or a pile of mulch. They come in many colors, shapes, and sizes. They can grow as fast as four to six inches per hour. Stinkhorns get their name from their foul odor, described by some people as a rotting meat smell. The smell attracts insects, which then spread the mushroom spores. While the smell is unappealing, stinkhorns are short-lived, and they help break down organic matter into the soil. They are most likely to appear in cool, wet weather. UC has management advice for mushrooms and other nuisance fungi in lawns.

More information: Stinkhorn Mushroom

Months applicable: January, February, March, October, November, December

Tags: Best Practices

Stone Fruit Hybrids

• Pluot and aprium: hybrids of a plum and an apricot, named for which fruit dominates.
• Plumcot: a 50–50 hybrid of a plum and an apricot.
• Peacotum: a hybrid of peach, apricot, and plum.
• Nectaplum: a hybrid of a nectarine and a plum.
• Cherum: a hybrid of a cherry and a plum.
• Peacherine and pectarine: hybrids of a peach and a nectarine.
• Nectarcot: a hybrid of a nectarine and an apricot.

Months applicable: March, April, May, June

Tags: Best Practices, Fruits & Nuts

Success with Houseplants

If you enjoy houseplants, Ernesto Sandoval, the Director of the UC Davis Botanical Conservatory can help. He has advice about selecting plants that tolerate the light and humidity levels of your home as well as tips about how to care for them. For instance: Overwatering is the number one killer of houseplants. Allow succulents to dry completely between watering. Water leafy plants that recover easily from wilting when they start to droop. For more information, including many useful tips, watch his video presentation: Growing Houseplants

Months applicable: Any month

Tags: Ornamental Plants

Sudden Oak Death

Sudden oak death is a disease of oak trees caused by an invasive plant pathogen, Phytophthora ramorum. It occurs in Santa Clara County as shown on this map. If your oak tree went from healthy (green) to dead (brown) with a full complement of dead lives on the tree, it might have died from sudden oak death. More details about what to do are available at UC Pest Note on Sudden Oak Death.

Months applicable: June

Tags: Disease, IPM, Trees & Shrubs

Summer Fruit Tree Pruning

Months applicable: July, August

Tags: Fruits & Nuts, Techniques

Summer Vegetables

Just because your summer vegetables are in the ground, beds, or containers, it doesn’t mean you can ignore them until it is time to harvest. And harvesting normally happens over weeks or months. Make sure you know what the vegetables will look like when mature; don’t be waiting for a green zebra tomato to turn red. Many vegetables are more tender when picked on the younger side. And they can go to seed and slow down production if left too long. Watering regularly is important. You need to water enough to get abundant production and make it worth the investment. Mulching and removing weeds will help conserve water for the vegetable plants. As with all plants, watch out for pests and diseases.

More information: Vegetable gardening

Months applicable: May, June, July, August, September

Tags: Techniques, Vegetables

Sunscald on Fruits and Vegetables

Fruits and vegetables can get sunburned in the summer heat. This is more commonly called sunscald and it frequently affects peppers, tomatoes, and persimmons. The leaves shield the produce from the sun, so it helps to make sure the plants have sufficient fertilizer and water for a healthy plant. You can cut out the damaged parts and eat the rest of the fruit.

Months applicable: July, August

Tags: Abiotic Disorders, Fruits & Nuts, IPM, Vegetables

Support Your Vegetables

Save garden space by providing good support systems for climbing or vining vegetables like tomatoes, pole beans, and cucumbers. Growing vertically also keeps plants healthier by improving air circulation, increasing sun exposure, and keeping fruits off the ground. Even shorter plants like peppers and eggplants benefit from support since heavy fruits can cause unsupported branches to break. There are many possible choices, from commercial cages and stakes to creative reuse solutions. It’s best to install the supports at planting time to avoid damaging the roots or breaking the stems of your new plants.

More Information: Trellising, Staking, and Caging

Months applicable: February, March, April, May, June

Tags: Best Practices, Techniques, Vegetables

Sweet Peas

Months applicable: February, March

Tags: Ornamental Plants, Techniques

Termites

Termites are very common in Santa Clara Valley. The first sign of infestation may be the presence of winged forms or fecal pellets pushed out of the infested wood.

See the UC Pest Note on Termites to identify which type is present and the methods of control. Learn all you can before calling in the professionals.

Months applicable: April, November

Tags: IPM, Trees & Shrubs

Testing Soil Moisture Depth

You know how long you water your garden, but do you know how deep the water is going? You don’t need an expensive moisture meter to check. A simple probe can help you find out. Use any item sturdy enough to push a foot or so into the soil, for example, a long screwdriver or metal rod. Push the probe directly into the soil using firm pressure. It will go through moist soil and stop when it hits the underlying dry soil, showing you how deep your water has penetrated. Watering deeply but infrequently is recommended.

More information: Checking Moisture Depth

Months applicable: June, July, August

Tags: Best Practices, Trees & Shrubs, Vegetables

Thyme

Months applicable: March, April, May, June, July

Tags: Herbs

Tick Information

Ticks are abundant after mild winters and they can carry dangerous diseases. To learn more about ticks, see the UC Pest Note on Lyme Disease. Be sure to visit the County of Santa Clara website for information about ticks.

Months applicable: June

Tags: IPM, Invertebrates

Time for Seed Saving

As we reach the end of the summer garden season, were there some vegetables you particularly loved this year? If yes, consider saving their seeds for next year’s garden. The easiest seeds to save are from self-pollinating plants like beans, peppers, lettuce, and tomatoes. Be aware that seeds from hybrid varieties may not breed true. Dry fruit plants like beans and peas can just be separated from their pods, dried, and stored. But tomatoes require a “wet” method where seeds are scooped into a container, fermented, washed, dried, and stored.

More information: How to Save Seeds

Months applicable: August, September, October

Tags: Techniques, Vegetables

Time to Prune Frost Damage

When there is still a danger of frost, we recommend leaving frost damage on plants so it provides protection to undamaged parts. Once the cold winter weather is behind us, it's time to prune frost-damaged plants. Pruning it off would stimulate tender growth that is susceptible to frost. Although the typical last frost date will vary depending on your location within the county and its microclimate, it’s time to start the spring cleanup soon.

More information: Treating Cold-Damaged Plants

Months applicable: March, April

Tags: Best Practices, Ornamental Plants, Trees & Shrubs

Today’s Grubs Are Tomorrow’s Beetles

The white grubs commonly found in lawns and gardens hatch into masked chafers and green fruit beetles. Masked chafer grubs are about 1 inch long and are mostly found in lawns. They feed on roots, so a large population can cause dead patches. You may also see lawn damage from animals digging for these tasty treats. The green fruit beetle grub is much larger, about 2 inches long, and is found in compost or garden beds high in organic matter. The grubs don’t damage plants, but the iridescent beetles feed on fruits. Finding an occasional grub is no cause for worry. Just leave them out for birds to feast on.

More Information: What are White Grubs?

Months applicable: April, May, June, July, August, September, October

Tags: Invertebrates

Tomatillo (Physalis philadelphica)

Tomatillos still to this day is a truly wild plant. Attempts to hybridize them have failed. The plant is native to Mexico and was brought to the U.S. by Mexican Indian immigrants. It has a tart green apple taste and is the main ingredient in green salsas. It is also used in soups, stews, and guacamole.

It is a member of the Solanaceae (nightshade) family as is the tomato and will grow any place a tomato will. It is fairly drought tolerant. Being a wild plant, there is a great deal of variability in plant habit, fruit size, etc. It is an annual, a low growing, sprawling plant usually not more than 2 feet high.

The tomatillo has small, sticky, tomato-like fruits enclosed in papery husks. They are 1 to 3 inches in diameter and green or purplish in color. Culture is very similar to that for tomatoes or peppers. Plantings are generally direct seeded. The first harvest is ready in 70 - 80 days. They are not ripe until the fruit begins to break through the husk.

Months applicable: June, July

Tags: Vegetables

Tomato Bottom Scarring

Sometimes scarring can be seen on the bottom (blossom end) of tomatoes. This can be caused by weather conditions such as cool and cloudy weather at bloom time, making the blossom stick longer to the small fruit. The fruit is perfectly good to eat with the damaged part cut out. Some large heirloom tomatoes are more susceptible to this condition.

Also known as catfacing.

Months applicable: June, July, August

Tags: Abiotic Disorders, IPM, Vegetables

Tomato Hornworm

Months applicable: June, July, August

Tags: Disease, IPM, Invertebrates, Vegetables, Vertebrates

Tomato Russet Mite

Tomato russet mites deplete juice from the cells of leaves, stems and fruit. They usually start at the base of the plant and move upward. If not controlled, these pests can kill plants. At first sign of damage, treat with sulfur dust or a spray solution of wettable sulfur and spreader-sticker. More information is found in the UC Pest Note on Tomato Russet Mite.

Months applicable: June, July, August

Tags: IPM, Vegetables

Tomato Staking

It's time to start planning how you will stake your tomatoes. You will want to stake your tomatoes right after you plant your seedlings. Here are the various Tomato Staking Techniques we have tried.

Months applicable: April, May, June

Tags: Vegetables

Tomato Suckers

Pinching out suckers is recommended for areas with a short growing season (for faster production) or humid summers (to improve air circulation) or to make it easier to tie plants to stakes. But with our dry climate and long growing season, there’s no need to remove them if you’re growing tomatoes in cages. Letting suckers grow provides foliage cover to shield the fruit from direct sun, gives additional photosynthesis, and will produce more fruit. Feel free to remove interior leaves that are shaded out or turning yellow, or clip foliage as needed to make the tomatoes easier to find and harvest. But no need to pinch out the suckers.

See Cultural Tips for Growing Tomatoes for information such as site selection, soil preparation, when to plant, etc. when growing tomatoes.

Months applicable: April, May, June

Tags: Best Practices, Techniques, Vegetables

Tomato blossom end rot

A brown depression on the bottom of tomatoes is usually blossom end rot (BER). This disorder is related to a calcium deficiency aggravated by irregular watering. Since most soils have adequate calcium, watering is usually the problem. Without regular watering, the calcium in the soil cannot reach the plant. Mulching can help. Water tomatoes regularly. Avoid flooding them so the roots sit in water. For more detailed information about BER please view Managing Blossom-End Rot in Tomatoes and Peppers.

Months applicable: July, August, September

Tags: Abiotic Disorders, IPM, Vegetables, Waterwise Tips

Transplanting Vegetables

Months applicable: February, March, April, May, June, July, August, September, October

Tags: Techniques

Travel rules for plants, seeds, and flowers

If you’re planning international travel, and there’s a chance you might want to bring plant or food products home, a little research in advance might be useful. The USDA has collaborated with the states of California, Florida, and Texas to create a website that tells you what you are and are not allowed to bring back home. Some plant products require a permit or other documentation which can take up to 30 business days to process. The website has contact information if it doesn’t answer all your questions. Don’t risk bringing plant pests or diseases back home.

More information: Travel rules for plants and flowers

Months applicable: Any month

Tags: Disease

Tree Suckers and Waterspouts

In order to keep your trees producing and growing efficiently, promptly remove any suckers coming from the roots, branches growing from beneath the graft union, and rapidly growing vertical shoots from the branches (waterspouts).

Months applicable: June

Tags: Best Practices, Techniques

Trees Planted Too Deeply

When you plant a tree or shrub, look for the root flare; it’s the point at the base of the trunk where the roots start. The soil should be at that level when you put the plant into the ground (or even into a new pot). Planting too deep can prevent the roots from getting the oxygen they need or cause the bark to deteriorate at ground level. Either can stunt plant growth, resulting in branch dieback or causing bark cracking. Don’t assume a container plant is at the correct level; you may need to remove soil to find the root flare.

More Information: Trees Planted Too Deeply

Months applicable: Any month

Tags: Ornamental Plants

Trees for Patios and Small Spaces

Non-aggressive root systems, no messy fruit, small size, relatively free from pests and attractiveness are some of the things to look for. Some examples are Japanese Maple, Chinese Pistachio (male), White or Pink Hybrid Crape Myrtle, Tollenson's Weeping Juniper, Flax-leaved Paperbark, Strawberry tree and Canadian Redbud. The Cal Poly SelecTree website lets you search for trees based on characteristics including size.

Months applicable: February

Tags: Best Practices

Tropical Flowers

If you have your heart set on tropical and subtropical plants like bougainvillea and hibiscus, planting in May will give them time to get established before the cold weather hits in the fall. Planting them in a protected area such as under eaves may keep you from having to cover them on cold nights.

Months applicable: May

Tags: Ornamental Plants

USDA Hardiness Zones

Planting zones help you select plants that are right for your garden. There are two systems, USDA and Sunset Western Garden.

USDA divides the US into hardiness zones based on average high and low temperatures. Most of Santa Clara County is in zones 9b and 10a.

Sunset makes many finer distinctions, taking into consideration rainfall patterns, ocean influence, and more. In the Sunset system, Santa Clara County is largely zones 15 or 16 with some zone 7 for areas with more extreme highs and lows. Sunset zone maps: Central and South County and North County.

For gardening success, choose plants known to thrive in your zone.

Months applicable: Any month

Tags: Best Practices, Fruits & Nuts, Garden Basics, Ornamental Plants, Trees & Shrubs, Vegetables

Under the tree

What’s happening under a tree can have a big impact on its success. Having a tree surrounded by a lawn is never ideal, mostly because of different watering needs. Grass needs frequent shallow watering, perhaps two or three times per week, while trees need infrequent deep watering, perhaps once a month. A tree with grass near its trunk can be injured by lawn mowers and weed trimmers, which then makes it easier for insects or diseases to enter the tree. Water from sprinklers can also damage the bark. Mulch under the canopy helps conserve moisture and reduce weed germination. Possible mulch materials are wood chips spread four to six inches thick or fallen leaves from a disease-free tree. Neither mulch, flowers, nor bushes should be close to the trunk because they can hold moisture against the trunk and cause crown rot, resulting in the slow death of the tree.

More information: Landscape Trees

Months applicable: Any month

Tags: Best Practices, Trees & Shrubs

Using Pesticides

Months applicable: Any month

Tags: Weeds

Vegetable Garden Check-In

This is a good time in the season to evaluate your vegetable garden to see what’s producing well, what you can improve, and what to give up on and chalk up to experience. Take notes! If a plant is barely growing, could it benefit from a shot of fertilizer or some extra water? Might you have planted it out too early in a cooler-than-usual spring when both daytime and nighttime temperatures were still too cool? If it’s not getting six to eight hours of sun per day, can you move it to another spot or put reflective material nearby to give extra sunlight? Did you use a new soil that perhaps had a different blend of materials? Is part of it being eaten or affected by the disease? Observe closely, including on the underside of leaves and at night. Harvest regularly and promptly. And remember the old gardening adage, “There’s always next year.”

More information: Vegetable Diagnostic

Months applicable: June, July

Tags: Best Practices, Vegetables

Vegetable Planting Chart

Wondering what vegetables can be planted now? To get the best success—whether planting from seed or transplants—refer to our Santa Clara County Vegetable Planting Chart. It's based on our own garden experiences.

Months applicable: February, March, May, June, July, August, October, Any month

Tags: Best Practices, Garden Basics, Herbs, Techniques, Vegetables

Verticillium Wilt

Verticillium wilt is a soil-borne fungal disease that damages plant veins. The damage is characterized by affecting one side of the plant. The leaves may wilt and turn brown, dying upward from the base of the branch to the tip. Dead leaves often fall, but may not. Mildly affected plants may survive if fertilized and encouraged into vigorous growth. The fungus can live for years in the soil.

Planting tomatoes, peppers, eggplants, and potatoes (all members of the Solanaceae or nightshade family) in the same place no more than once every three years helps reduce the fungal population to non-harmful levels. Soil solarization may eliminate Verticillium wilt from infected soils. Crop rotation with cereals or broccolis can reduce the pathogen. Avoid high nitrogen fertilizers. Plant Verticillium wilt-resistant varieties of tomatoes, potatoes or strawberries. Refer to the UC Pest Note information on Tomato, Potato, and Strawberry for species-specific suggestions.

Months applicable: May, June, July, August

Tags: Disease, IPM, Vegetables

Vinegar as Weed Control

Vinegar can work as a weed killer, but its effectiveness is limited. Household white vinegar (5% acetic acid) is too weak to kill anything other than tiny seedlings. Stronger horticultural vinegars with 20% acetic acid provide better weed control but typically only for annual, not perennial, weeds. And the higher concentration can be dangerous—including skin burns and eye injury—if not handled carefully. For comprehensive guidance on weed management in landscapes, refer to the University of California’s Weed Management in Landscapes recommendations.

Months applicable: Any month

Tags: Techniques, Weeds

Water Budgeting

Months applicable: May, June, July, August

Tags: Fruits & Nuts, Irrigation, Ornamental Plants, Trees & Shrubs, Vegetables, Waterwise Plants, Waterwise Tips

Water the Roots, Not the Plants

It's tempting to get the hose out and spray your dry, thirsty plants, but you don't want to waste water. Keep their feet nice and cool, but resist the urge to squirt the leaves unless they need a cleaning (for dust or white fly for instance).

It's a common belief that daytime water on the leaves will burn them. While it's possible, according to scientists—for hairy leafed plants where water droplets are held above the leaf surface—but not very likely. It's more the water will simply evaporate and not do your plants much good and could encourage fungal pathogens if wet overnight.

Months applicable: June, July, August

Tags: Irrigation, Waterwise Tips

Watering Hydrophobic Soil

Just as a dry sponge repels water, overly dry soil can do the same thing. This dried out soil is called hydrophobic. Hydrophobic soil can waste a lot of water as water drains away from the plant's root zone.

In pots: learn more about how to re-wet very dry soil on our Watering Hydrophobic Soil page. In the yard: setting sprinklers to run for 5 minutes, waiting for the water to soak in, and then running for a longer time can prevent water loss due to hydrophobic soil.

Months applicable: May, June, July, August

Tags: Irrigation, Techniques, Waterwise Tips

Watering Tomatoes

If you haven't already, it's time to cut back on watering tomatoes. Tomatoes have far more flavor when the ripening fruit is deprived of water. Don't forget to remove competing weeds from around the garden.

Months applicable: July

Tags: Best Practices

Watering Trees

The amount of water trees need in the summer depends in large part on the age of the tree. Newly planted trees with shallow roots may need weekly water. Trees that are a few years old and fairly well established may need monthly watering. Mature trees with extensive root systems may not need any supplemental water. These are just VERY general guidelines. It is essential to know the water requirements of the plants. You can determine these by researching cultural needs or knowing their native habitats, the soil type and how well it retains water, and the micro-climate in which the tree is located, e.g., shaded, windy, dry. The UC WUCOLS database has information on the water needs of over 3,500 plants used in California landscapes. Always water slowly and deeply to penetrate down to the roots. Use a soaker or drip hose around the tree at the drip line and let it slowly drip for 2 to 3 hours. Don't let lawn sprinklers hit tree trunks as this may cause crown rot and damage the tree.

Months applicable: July, August, September

Tags: Irrigation, Trees & Shrubs

Weed Management

While some weeds are edible (purslane, nettles, dandelions, miner's lettuce), many are a nuisance and compete with your chosen plants for water and nutrients.

Months applicable: January, February, March, Any month

Tags: Best Practices, IPM, Weeds

Weed Spotlight - Bindweed

Have you seen a pretty, morning glory-like flower on a vine that winds through any plant within reach? Field bindweed is one of the most challenging weeds to control because its roots can reach depths of 20 feet or more and it readily re-grows from root fragments as short as 2 inches. The only chance of controlling this invasive weed is to stay right on top of it and remove it as soon as you see any of it peeking up out of the ground. Every time it starts growing above ground and photosynthesizing, it is storing energy in the roots. This allows it to put out new shoots. It produces many seeds which remain viable for years. Making things even worse, it’s drought tolerant. Controlling it isn’t easy, but the UC pest note below discusses options. Chemicals aren’t needed if you’re persistent in removing new growth to prevent seed production and limit the plant’s ability to store new energy in the roots.

For more information: