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 trees and shrubs need deep watering every one to two weeks. Be sure to keep water away from the trunk.
- Check compost piles and keep them moist as a wrung-out sponge.
- Add mulch if less than 3” deep.
- Remove summer weeds before they set seed.
- Mow lawns frequently; water deeply several times a week. Dig and remove weeds.
- 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
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.