Monthly tips are categorized by: To-Dos, What to Plant, or Pests and Diseases. Scroll through the list to see items in each category.
To extend your basil harvest, pinch the flowers off the tips as soon as they start to develop to prevent the plant from developing seeds. When selecting leaves for eating, choose young leaves at the top of the plant and cut the stem at that point. This will help the plant branch out as it produces new growth.- June, July
- 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.- May, June
- Citrus Fertilizing
In California, most soils contain adequate nutrients for citrus growth, except nitrogen. 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 three different feedings in April, June and August.
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.
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.- January, February, March, April, May, June, July, August, September, October, November, December
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.- April, May, June, July, August, September
- 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).- March, April, May, June, July, August, September
- 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.- May, June, July, August
- 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 or a farm selling directly to consumers. The County of Santa Clara website has a Farmers Market page with links to certified Farmers Markets and the Country Crossroads map shows where you can buy more than 100 commodities directly the farm source.- June, July, August, September
- Garlic Harvesting
If you can't smell the garlic from your home in the mornings like so many Valley residents can, then all you need to do is check the Gilroy Garlic Festival dates to know it's harvest time! I use the "stop watering Mother's Day, harvest on Father's Day" advice to remind myself, but anytime late June or early July you should start looking closely at your plants. Because it's an underground harvest, timing is more important; harvest too early and the shelf life diminishes; harvest too late and the garlic can be overripe. Generally, you'd like to see the lower leaves brown and some green still on the upper leaves. After digging up, put the garlic out of direct sunlight in a place with good air circulation. The University of California Vegetable Research Center has additional general Information on Garlic (including recommended varieties and problem diagnosis info). See UC Pest Note on Onions and Garlic for diseases and pests that affect garlic.
When harvesting save the biggest bulbs of garlic. If you save the biggest of the bulbs, you can plant those cloves again next year increasing your odds for a great crop. The UC Master Gardeners of Napa County have more information about Growing Garlic.- June, July
- 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.- June
- Irrigation and Graywater
As temperatures rise, irrigation becomes more important. Container plants will begin to dry out and need to be checked every few days. Inspect irrigation systems for leaks, clogged drip emitters, misaligned sprinkler heads, and other problems which could waste water. Make sure the water is going to the root zones of the plants.
Things to consider:
Use a smart irrigation controller. These help adjust watering based on local conditions. Learn more about smart controllers.
Collect water from the shower as it heats up and use it to water any plants.
Use graywater from garage sinks and washing machines to water ornamentals and lawns. UC has a publication titled Use of Graywater in Urban Landscapes in California.- April, May, June, July, August
- Lawn Care
If you have a lawn, be sure to water it as early in the morning as possible to avoid evaporation. This also helps reduce fungal diseases by giving 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.
Check lawns for weeds such as spurge, burr clover, and whatever happens to invade your neighborhood. When mowing in the summer, set the blade height as high as you are comfortable with—taller grass shades the soil, reducing evaporation and protecting valuable earthworms in the soil. Use the UC Guide to Healthy Lawns to learn more about mowing, irrigating, fertilizing, detaching and aerating. Better yet, take advantage of the County's Lawn Replacement Program!- May, June, July, August, September
- Mulch - a Gardener's Best Friend
Mulching around your plants has many benefits. It holds in moisture by reducing evaporation from the soil, keeps weed seeds from being able to germinate, and moderates the temperature of the soil so that it doesn't vary as much with direct sun and changes in air temperature. Mulching can cool the soil for plants like blueberries and it will help hold some heat in for summer vegetables as the air gets cooler.
Mulch will guard against soil erosion when the rains start. Organic mulch such as wood chips or bark will slowly break down and improve your soil over time.
It is recommended to keep mulch six inches away from trunks and twelve inches away from buildings. If you are confused about the difference between compost and mulch, then UCCE's Soil Management - Compost versus Mulch Comparison will help.
Many local tree trimming companies are happy to deliver free wood trimmings that can excellent mulch - just be sure that the trimmings are disease- and palm- and eucalyptus- free. This can be hard to guarantee. Straw (not hay) from the local feed store can also be inexpensive, effective mulch.- May, June, July, August, September
- Pruning Roses to Minimize Disease
A chemical-free way to keep roses healthy and minimize disease associated with foggy summer mornings is to prune to improve air circulation. Think of your rose bushes as large vases, with open centers. Good air circulation allows the morning dew to dry, and helps prevent rust and powdery mildew. UCCE's Center for Landscape and Urban Horticulture has more info about the Fundamentals of Pruning Roses. The UC Pest Note on Roses has more about general cultural practices and weed control.- May, June, July, August
- Soil Solarization
Soil solarization can be used to control diseases, nematodes and weeds by baking everything under plastic sheeting.The best time for solarization of soil is from June to August. Leave the soil covered for 4 –6 weeks. Refer to the UC Pest Note on Soil Solarization for Gardens & Landscapes.- June, July, August
- 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.
*file245851*- June, July, August
- 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).- June
- 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). While it's a common belief that daytime water on the leaves will burn them, it's not very likely based on a study by scientists - the water will evaporate and not do your plants much good during the day, and could encourage fungal pathogens if wet overnight.- June, July, August
- 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.- May, June, July, August
- Worm Composting
Worm composting also called vermiculture or vermi-composting is a convenient way to decompose kitchen waste and provide nutrient-rich soil amendments for your vegetable garden.
Here is a description for Getting Started.
2. What to plant
- 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. They're Honey Bee Haven website has more resources, including a list of plants they grow.- March, April, May, June, September, October
- 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 timber lands."
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). For details and recommended alternatives, please consult their Website.- April, May, June, July, August, September
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. Echeverias do 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,- June
- 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-poded 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.- May, June
Milkweeds are the required host plants for monarch butterflies. Milkweeds provide food for the caterpillar, nectar for the butterfly, and chemical compounds that make the monarchs distasteful to predators. Make sure to choose a variety native to California. The non-native Tropical Milkweed may disrupt monarch migration patterns, because of it's longer growing season, so don't plant it unless you're willing to cut it back to 6" or less from Oct-Feb. Learn more at the UC ANR blog posting on Overwintering Monarchs.- May, June
- 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.- June
- 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.- March, April, May, June
- 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.- June, July
- 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.- February, March, May, June, July, August, November
- Vegetables Grown 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. 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 or using an inexpensive moisture meter. 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.- May, June
3. Pests and Diseases
- 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.
Ants are among the most prevalent pests in households. UC IPM offers steps to follow in an Ant Emergency.
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.- June, July, August
- 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.- June
- 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.- May, June
- Codling Moth
"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 coddling 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 is a very labor intensive method. Heavy infestations may require the use of pesticides on the moths, before fruit is affected. For more information, refer to the UC Pest Note on Codling Moths.- March, April, May, June, August, September, October, November
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. Another method of control is a covered container such as a small margarine tub with holes cut halfway up the sides. Pour in about an inch of soy sauce and a thin layer of vegetable oil in the container and bury up to the holes. Empty as needed. Other control methods are described in the UC Pest Note on Earwigs.- May, June
- 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.- May, June
- Fire Blight
Late spring and early summer are the time fire blight shows itself. Fire blight is a bacterial disease that makes plants look as though they have been damaged by fire. It attacks apples, pear and quince, most often, but can also infect ornamentals, such as toyon and pyracantha. Very often, the growing tip folds over into a shepherd’s crook shape.
Fire blight spends the winter in cankers or wounds on the plant and resumes bacterial growth in the spring. There may be oozing from the canker. It is spread by insects, rain, or pruning. Infection can extend into limbs, trunks, or the root system and June kill the tree. Complete removal of any diseased tissue is critical. Dip clippers into a 1 part bleach, 9 parts water solution between each cut to prevent reinfection. The final cut should be 8-12 inches below the diseased area. The UC Pest Note on Fire Blight contains photos and more information.- April, May, June
- 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.- June, July
Our local gophers are also called pocket gophers. They make their presence known with crescent shaped mounds of dirt in the garden. Snacking on plant and tree roots as they tunnel through the soil, they are active year round and can have up to three litters each season in well-watered areas. Gophers also gnaw on irrigation lines and divert water into their tunnels, making it difficult to properly water plants. Adults live about three years. Homeowners can use several methods to control them. Locating the main tunnel is the first step. Placing Macabee or Gophinator or box traps or poison baits are explained in detail in the UC Pest Note on Gophers. Another method involves excluding them with wire fencing. Ultrasonic devices and chewing gum have been tested and are not considered to be effective.- May, June, July
- Integrated Pest Management and Beneficial Insects
Our gardens contain far more beneficial insects than pests. Any time pesticides are used, both good and bad insects die. This upsets garden ecosystems. Use of pesticides can also pollute waterways and may put our children and pets at risk, along with other environmental consequences. We can dramatically reduce pest problems by practicing Integrated Pest Management, which includes planting native species, following good cultural practices, and encouraging beneficial insects, such as lady beetles, lacewings and soldier beetles- March, April, May, June, July, August, September, October
- Mosquitoes May Be Breeding In Your Yard
According to Santa Clara County Vector Control, many people are unaware they may be raising mosquitoes in their backyard, they offer tips on identifying possible Mosquito Breeding Grounds. UC has created a video titled Don't Let Mosquitoes Breed in Your Yard.- May, June, July, August, September, October
- Powdery Mildew
Powdery mildew fungus is a common disease on many plants and produces a white powdery appearance on leaves and sometimes other green parts. It can be found on roses, dahlias, chrysanthemums, peas and squash. Some rose varieties are so susceptible that you would be better off removing the plant.
Powdery mildew likes warm days and cool nights. General tips: maintain good air circulation, remove summer veggies if heavily infected and clean up well, and plant resistant varieties next year.
Powdery mildew is difficult to treat—the best method of control is prevention by planting resistant varieties—treatments are discussed in the UC Pest Note on Powdery Mildew and the UC Pest Note for Powdery Mildew on Fruits and Berries.- May, June, September, October
- Rose Care
A chemical-free way to keep roses healthy and minimize disease associated with foggy summer mornings is to prune to improve air circulation. Think of your rose bushes as large vases, with open centers. Good air circulation allows the morning dew to dry, and helps prevent rust and powdery mildew. The UC Pest Note on Roses has useful information about rose cultivation, pests, and pruning.- May, June
- Snails and Slugs
Snails and slugs are patrolling your garden right now looking for new growth. Our preferred non-toxic method for dealing with them is to handpick early in the morning, or at night by flashlight. They can be saved for your friends with chickens, or crushed in place. If you do use snail bait, those made with iron phosphate are not toxic to pets and wildlife and they work well enough. For a full run-down of which management methods work, see the UC Pest Note on Snails and Slugs.- February, March, April, June, October
- 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.- May, June
- Squirrel Control
Squirrels can be particularly annoying because they tend to take one bite out of each piece of fruit, rather than eating the whole thing and leaving the other fruit intact. They are difficult to control, but you can try some of the methods recommended in UC Pest Note on Tree Squirrels and UC Pest Note on Ground Squirrels.- June, July, August
- 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.- June
- Tick Information
Ticks are abundant after mild winters and they can carry dangerous diseases. To learn more about ticks, see this Consumer Reports article on tick season or the UC Pest Note on Lyme Disease. Be sure to visit the County of Santa Clara website for the percentage of ticks testing positive for Lyme disease in several popular parks.- June
- 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 ia found in UC Pest Note on Tomato Russet Mite.- June, July, August
- 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.- May, June, July, August
- Weed Management
Whichever 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 go to seed, and when the ground is moist. Hand pulling and hoeing are effective methods for killing many common weeds. Knowing what kind of weeds you have can be helpful in choosing the best management method - to learn more, see UC's Weed Gallery for help identifying weeds and the UC Pest Note on Weed Management in Landscapes for information about control.- February, March, April, May, June, July
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.- June, July, August, September
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.