March Tips
Monthly tips are categorized by To-Dos, What to Plant, or Pests and Diseases. Scroll through the list to see items in each category. Also, refer to our list of tips useful for any month.
1. To-do
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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
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Pruning Dead Branches
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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.
- March, April -
Wet Soil
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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.
- February, March, December -
Bulb Care and Clean-up
- Tulip bakeri ‘Lilac Wonder' from Allen Buchinski
that are mushy or show other signs of rot. And continue to enjoy easy-maintenance flowers year after year. For more information see UCCE Tips on Flowering Bulb Care.
- March, April -
Growing Vegetables in Containers
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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.
- February, March, April, October, November -
Poison Oak
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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.
- February, March, April, November -
Weed Management
- Photo: Oxalis pes-caprae aka Bermuda buttercup, by Joseph DiTomaso, UC ANRWhichever variation of “One year’s seeds makes seven years’ weeds” you prefer, the truth remains: a key part of weed control is not letting them go to seed. For best results, work on removing weeds before they are able to propagate. Hand pulling and hoeing are effective methods for killing many common weeds.Knowing what kind of weeds you have and how it propagates can be helpful in choosing the best management method. If they propagate by seed, pull or hoe them before they flower and go to seed. If they re-grow from roots, pull up as much of the root as possible. Many weeds, like Bermuda grass, have multiple ways of multiplying. Only non-propagating parts are advisable to throw in the compost bin.More Information: UC Quick Tips on Weeds in Landscapes
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Soil Management - Compost vs Mulch
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Many home gardeners are confused about the terms “compost” and “mulch;” frequently these terms are used interchangeably, but they are not really the same thing. Here is a Comparison of Soil and Mulch from UCCE.
Amend soil with compost to create soil that will retain water but still drain well enough for roots to have the air and water they need.
Benefits of compost
- Forms aggregate particles with clay
- Creates larger pore spaces for water & air
- Helps release nutrients from clay so that plant roots can absorb them
- Supports the soil foodweb by providing nutrients for the organisms
- Lowers pH somewhat.Benefits of mulch
Mulch does not get worked into the soil. It sits on top of your irrigation system and helps:- Control weeds
- March, April, May, Any month
- Prevent erosion
- Preserve soil moisture
- Keep roots cool and moist -
Lady Beetle Larva
- Lady beetles develop through four life stages: egg, larva, pupa, and adult by Jack Kelly Clark, UCANR
For more information: Aphid Eaters
- March, April, May, June, July, August -
Sheet Mulching - "Lose the Lawn"
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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.
- March -
Empty Standing Water
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More information: Empty Standing Water Video
- March, April, May -
Yellow Leaves on Citrus Trees
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More information: Growing Great Citrus
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Leafy Salad Plants
- More Information: Growing lettuce in Santa Clara County
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Transplanting Vegetables
- More information: Vegetable Planting Handbook (Los Angeles Master Gardeners)
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Garden Planning in a Drought
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More information: Drought: Gardening Tips
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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
- March, April, May, June, July, August, September, Any month -
Drought tip - Lawns
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More information: Drought Resources
- March, April, May, June, July, August, September, Any month -
Pruning Fruit Trees
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- Horizontal branches generally produce more fruit.
- Sun exposed branches produce the largest fruit. Shaded branches eventually stop fruiting and will never produce again without drastic pruning.
- New growth occurs right where you make the cut; the influence of the cut only affects the buds within 1”– 8” of the cut.
More information: Fruit Tree Pruning Resources
- January, February, March -
Frost Dates
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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
- January, February, March, November, December -
Shovel Pruning
- Sometimes a plant just isn’t working out in your garden and it comes time to part ways. The most drastic form of pruning is “shovel pruning” where you finally just dig the plant out. Another term for this technique is “editing the garden.” Perhaps you saw a plant you liked in another part of the country or world. If that other location had a different climate or soil type, it may not translate well to sunny, dry California with our clay soils. Perhaps you want to garden organically but the plant has too many pests or diseases and you are having trouble controlling them with organic methods. Or maybe it simply doesn’t resemble what the tag promised. It’s okay to let go. Spring and Fall are good times for new plantings, so it is also a good time to reassess the appropriateness of what’s in your yard.
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Raised Beds
- Raised beds make gardening easier in several ways. You don’t have to bend over as far to reach the surface. You can add any soil blend you like and you won’t compact the soil around the roots by walking on it. You can also better protect the roots and plants from critters. You can build them with wood or cinder blocks or anything that doesn’t have chemicals that can leach out into your food, for example, no pressure-treated lumber or railroad ties with creosote. If you’re using wood, redwood and cedar are the most resistant to pests and rot. You can be particularly green by using old fence boards or decking. Locate the beds where the plants will get the sun they need. Make sure the width is not more than twice your arm length so that you can easily reach all parts from the sides. To prevent gophers and other pests from tunneling into the root area, line the bottom of the bed with hardware cloth.More Information: Gardening in Raised Beds (Page 7)
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Time to Prune Frost Damage
- Frost damage on pelargonium
More information: Treating Cold-Damaged Plants
- March, April -
Potting Mix vs Planting Mix
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For more information: Bagged Potting Mixes
- March, April, May, November -
Weed Focus: Spotted Spurge
- For more information: Spotted Spurge Management Guidelines
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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.More Information: Marin Master Gardeners: Vines
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Certified Arborists
- Whether you prune your own trees or hire someone, it’s important that whoever does the job knows at least a little about tree anatomy, plant health, and the purpose of the plant (shade? privacy? fruit?). Knowing the difference between heading cuts and thinning cuts, how to locate a node to direct growth, and how to open up a tree for air circulation are all part of good tree pruning. An improper pruning job can stress the tree, spread disease, invite pests, and promote weak branching. These can lead to breakage, damage, and injury. The cheapest bid may end up costing more in the long run due to damage repair, lawsuits, and additional fix-it pruning. Take a class or read tree pruning guides if you want to do a good job yourself. If you hire someone, it is strongly recommended that you choose a certified arborist who has been specially trained and is insured. The International Society of Arboriculture can help you find a certified arborist in your area.More Information: Tree Pruning Guide
2. What to plant
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Asian Vegetables
- You can easily grow some vegetables used in different types of Asian cuisine and found in Asian markets. They are not necessarily native to Asia but have found their way into various cuisines. One way to decide which food to grow yourself is to choose varieties that aren't readily available or are more expensive in your local markets. It’s also fun to impress your family, friends, and neighbors with something they may not have seen growing before. Possibilities include sesame seeds, bitter melon, opo, sigua (loofah) in summer and bok choy, napa cabbage, daikon radishes, gai choy in spring or winter.
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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.More Information: Seed Saving
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Thyme
- Thyme is much more than an herb to season food. In ancient times it was brewed by Egyptians for mummification, bathed in by Greek soldiers for courage in battle, and used by the Sumerians as an antiseptic and antifungal. And if you want a real surprise, check out the active ingredient list on a bottle of Listerine mouthwash. In your own garden it can be used for culinary purposes or as a purely ornamental landscape feature. It grows best in well-drained soil and sunshine, although it will tolerate some shade. It is quite drought tolerant once established. Common/garden thyme (Thymus vulgaris) is an excellent all-purpose thyme, growing to a foot tall and up to two feet wide. Lemon thyme (Thymus citriodorus), with its lemon scent, makes a nice evergreen border. Creeping thyme (Thymus serpyllum) stays short and can be used as a ground cover or between stepping stones. Thyme is attractive to butterflies and bees.More Information: Growing and Using Thyme
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Herbs
- Many herbs can be grown both indoors and out, in pots or in the ground. Rosemary grows large and needs to be in the ground or a big pot. If you use basil to make pesto, you may want a row of it in the garden. Yet most herbs tend to be used in small quantities for seasoning and so they can be grown in small containers. They can be on the kitchen counter or a windowsill for ease of use in cooking. They can be on a patio if you are in an apartment or condo. And they are well suited to container gardening outdoors. Woody herbs can be grown from cuttings, lemongrass can be started from stalks from the store, and most others can be started from seed. After harvesting, many can be dried as well as used fresh.More Information: Growing Herbs
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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.More Information: Vegetable Seed Viability
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Camellias
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More information: Camellia Pests
- January, February, March, April, May, September, October, November, December -
California Natives
- More Information: California Native Society
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Chayote
- More information: How to grow chayote video
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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.
More Information: Peas
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Sweet Peas
- You have probably heard people use the "sweet peas" term incorrectly. In garden terminology, sweet peas are flowers. They are not edible and are poisonous. Edible peas, even if sweet in taste, are not correctly called sweet peas. Sweet peas are incredibly fragrant vining flowers that come in a variety of colors, mostly pastels. They are an annual flower so they must be planted again every year. You can sow seeds anytime during the winter for spring bloom. The seeds are hard and it can be helpful to nick them slightly before putting them in the ground. Sweet peas do best in full sun or light shade. The plants will decline when it gets hot outside and they will need to be removed. Remember, you cannot eat sweet peas.
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When to Start Seedlings for Summer Vegetables
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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
- February, March, April, September -
Second Round of Cool-Season Veggies
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More information: Vegetable Planting Chart
- January, February, March -
Bare Root Plants
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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
- January, February, March -
Plant Asparagus Crowns
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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.
- January, February, March -
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
- February, March, October, November -
Attracting Bees
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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.
- March, April, May, June, September, October -
Cool-Season Vegetables
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If your summer vegetables are still going strong, you can start seeds in August in pots and transplant them later when you remove your summer crops. You can direct seed them on the ground if you have the space. The soil should still be warm enough for seeds to germinate. 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.
If starting from seed, follow package instructions or plant them about two times as deep as the seed is wide. Leave space between seeds to account for the eventual size of the plant. Keep the seeds moist until they germinate, then gradually reduce the watering frequency as they grow.
More Information: Vegetable Planting Chart
- February, March, August, September, October -
Plants to Attract Butterflies
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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.
- March, April, May, June -
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.
More information: Growing Transplants from Seeds
- February, March, April -
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.
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Flowers To Attract Beneficial Insects
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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:
- March
UC Pest Note on Biological Control and Natural Enemies of Invertebrates
UCCE notes on Attracting Beneficial Insects to Your Garden.
3. Pests and Diseases
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Snails and Slugs
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More information: Snails and Slugs
- January, February, March, April, December -
Camellia Petal Blight
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More information: Camellias Petal Blight
- March -
Brown Rot on Apricot and Peaches
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- MarchIf 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.
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Rat Management
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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
- January, February, March, April, July, August, September, Any month -
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.
- March -
Citrus Leaf Drop
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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.
- March, April -
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.
More Information: Brown Marmorated Stick Bug Pest Note -
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.Mix the horticultural oil in a sprayer and apply it according to directions on the packaging. Never use more than what is prescribed. Make sure to complete the spraying before the trees start to bud and blossom so as not to damage developing flowers and fruit.More Information: Calendar of Backyard Gardening Operations for Selected Fruit and Nut Trees and Dormant Spraying of Fruit Trees
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Slime Molds
- Slime molds come in a variety of colors and shapes. They often appear suddenly and look worrisome. They are fungi and need moisture to grow. According to the Mississippi State Extension, “when slime molds find something to eat, they surround their food and then swallow it. Slime molds may feed indirectly on dissolved substances escaping from organic matter, but they usually feed on microorganisms such as bacteria.” In general, no action is needed. When the area dries out, the slime mold will disappear. Just enjoy this marvel of nature while it’s there.