July in the Contra Costa Garden
July Garden To Dos
General Garden Care
- Protect your skin. Wear sunscreen or hats when gardening during the daylight hours!!
- Check irrigation systems. ET (evapotranspiration) rates are high, and many trees and shrubs need deep watering every one to two weeks. Be sure to keep water away from the trunk. See Your Landscape During Drought on our drought tips page for information on helping your larger landscape plants survive a drought.
- In serious drought conditions, consider reducing lawn watering to deficit or even survival levels. See Your Lawn During Drought on our drought tips page for more information.
- Check compost piles and keep them moist as a wrung-out sponge.
- Add mulch to garden beds if it's less than 3” deep. If the mulch is very fine textured, keep it at about 2" to allow air circulation.
- Remove summer weeds before they set seed.
- Check bait stations for yellow jackets (ground wasps) and ants. Replace as needed.
Fruits & Vegetables
- Prune fruit-bearing plants: Prune cherries and early plums. Cut back cane berries (blackberries, raspberries and boysenberries) when finished bearing. Remove old growth and stake new canes.
- Clean up fallen fruit routinely.
- Fertilize citrus; use finished compost to top-dress plants.
- Stake tomatoes & beans.
- Start seeds for your winter vegetable garden. As difficult as it is to believe, now is the time!
Flowers & Landscaping
- Plant chrysanthemums, asters, Epilobium californicum (aka California fuchsia or Zauschneria) for fall color.
- Fertilize roses and container plants. Use finished compost to top-dress plants.
- Stake delphiniums, gladiolus.
Garden Pests & Diseases
- Check fruit trees—pick up all fallen fruit, check for ant trails, aphid and scale populations. Look for fire blight or brown rot symptoms.
- Spray with insecticidal soaps if aphids or scale have become major problems.
- Control budworms on geraniums, roses, Nicotiana, Penstemon and petunias with Bt (Bacillus thuringiensis) treatments.
- Control cabbage worms on Brassicas with Bt as well.
- Handpick stinkbugs, squash bugs, tomato hornworm and cucumber beetles in vegetable gardens.
- Treat for Tomato Russet Mite, the most common and probably least recognized tomato problem. Stems become bronze. Can be controlled with a thorough applications of wettable sulfur mixed in a pump sprayer with a spreader-sticker. Do not spray sulfur if temperatures are expected to be above 90°F.
- Watch for Verticillium and Fusarium wilt symptoms on tomatoes. Remove plants if affected.
For More Information
- UC IPM Pest Note on Aphids
- UC IPM page on Brown Rot
- UC IPM Pest Note on Earwigs
- UC IPM Pest Note on Fire Blight
- UC IPM page on Fusarium Wilt
- UC IPM Pest Note on Powdery Mildew
- UC IPM page on Rusts
- UC IPM Pest Note on Scale
- UC IPM Pest Note on Snails & Slugs
- UC IPM Pest Management Guidelines on Tomato Russet Mite
- UC IPM page on Verticillium Wilt
- UC Pesticide info on Bacillus thuringiensis
Local Weather Information
Linked data is from the California Irrigation Management Information System (CIMIS) weather stations. Visit CIMIS web site.
Contra Costa County Stations
USDA zones range from 8-9B
Sunset zones range from 7-17
Average min. temp. 54.2°F, 11.3°C
Average max. temp. 85.7°F, 29.8°C
Average rainfall 0.02”, 0.05 cm.