UC Master Gardeners of Riverside County

Desert Events & Updates

August 2023

August Gardening Tips

Maintenance

• Continue mulching to conserve soil moisture and control weeds.
• Keep harvesting vegetables for continued production.
• Do the final pruning of summer for fruit bushes.
• Prune apricots to avoid Eutypa fundus. Remove about 20% of this year's growth.
• To prevent the spread of brown rot, clean up debris around fruit trees and pick up dropped fruit.
• Control salt build-up on indoor plants; hose off the leaves and flush the soil with ample water.
• Attach bands of corrugated cardboard aorund apple tree trunks to trap codling moth larvae.

Fertilize

• Camellias, azaleas, and gardenias with chelated iron if there is yellowing between the leaf veins.
• Indoor plants
• Strawberries
• Mature fruit trees (after picking fruit) with Nitrogen and water
• Roses, six weeks after last application
• Last feeding of the year for citrus and avocados
• Chrysanthemums (until the buds start to open)
• Begonias, fuchsias, annuals and container plants

Flowers:

• Seed winter annuals this month. 
• Sow seeds of perennials in flats or pots for transplanting in October. 
• Try thrift, yarrow, coneflower and salvia. 

Vegetables:

• In a cool location indoors, start seeds of cabbage, broccoli, cauliflower, kale, bunching onion, and radicchio for over-wintering. 
• Direct seed oriental greens, beets, carrots, lettuce, turnips, Florence fennel, mustard, radish, rutabaga, spinach, and leeks.

Agave and yucca weevils—Scyphophorus

Direct control of agave and yucca weevils is difficult; even with regular inspection of hosts, the insects are often not observed until the plant starts to collapse. Preventive measures are the only effective controls.

Provide plants with good growing conditions and proper cultural care. Agave and yucca require well drained soils, full sun, and little or no irrigation after they become established. Plant on a mound or raised bed to improve soil drainage. Where feasible, before planting amend soil with sand or other porous materials to improve drainage. Minimize irrigation of established hosts. After any irrigation, allow topsoil to dry between watering events.

Larvae bore in the base of hosts, causing plants to decline and facilitating entry of plant pathogens. Larval feeding in combination with decay microorganisms that colonize wounded tissue commonly cause infested plants to collapse and die. Learn More

To help protect nearby hosts, remove dying hosts and the immediately adjacent soil where larvae may be pupating. Promptly dispose of infested material in ways that prevent weevils from emerging or escaping. Where agave weevil has been a problem, consider planting the smaller, narrower-leaved agave species. If applied BEFORE plants become infested, certain systemic insecticides (e.g., imidacloprid) may provide control.

UC Master Gardeners are available and hope to see you at these Certified Farmers Markets:

PALM SPRINGS 

Saturdays, Aug 12 & 26 - 8am - 1:00 pm

Palm Springs Pavilion - 401 S Pavilion Way, Palm Springs, CA, 92264

Riverside Downtown

Saturday, Aug 5, from 8:00 am to 1:30 pm, Main Street between 5th & 6th

High Temperature Injury

Plants are injured if temperatures become too high in the canopy or root zone, dehydrating tissues and killing plant cells. Damage is more likely the longer plants are exposed to excess heat and if they are moisture stressed, otherwise unhealthy, young, or a species more susceptible to high temperatures.

Solutions

To avoid high-temperature injury to roots, plant properly, provide sufficient soil volume for root growth as plants mature, and irrigate adequately. Apply organic mulch on top of the soil. Shade the sides of containers and planting boxes.

Avoid planting near heat sources and choose species well adapted to local conditions. For example, giant sequoia, Monterey pine, and other species adapted to cool growing conditions become damaged or killed when planted where summers are hot, as in most inland valleys of California.

Before mixing organic matter into soil, compost it well. If topsoil is amended with undecomposed organic matter at more than about 20% of topsoil volume, do not plant in it until after soil has been moist and warm for 2 months or longer to provide time for decomposition. Learn More

Advice to Grow by…Ask Us!

Have a Gardening Question...Ask our UC Master Gardener of Riverside County Helpline!

Please include as much detail as possible along with any relevant photos that illustrate your problem/question.

This service is free of charge and is provided year-round by UC Master Gardener of Riverside County Volunteers.

Email your question(s) to:

Desert Area: anrmgindio@ucanr.edu

West County: anrmgriverside@ucanr.edu 

Permaculture at RCRCD will present an introduction to Permaculture Design plus orient you to what we have planned for the year. Learn More

Visit RCRCD, Riverside-Corona Research Conservation District, at 4500 Glenwood Drive, Riverside, for free Rainwater Harvesting Workshop on Sat, Sept 2, 2023, from 10 - 11:30am.

Top Five Reasons to Compost

1. Composting reduces waste, makes us less dependent on landfills, and decreases greenhouse gas emissions.

2. Compost strengthens soil and promotes healthy plant growth.

3. Composting reduces the need for pesticides and synthetic fertilizers.

4. Composting recycles essential nutrients back into the soil.

5. Compost promotes a prolific soil ecosystem. (source)

Riverside County Master Gardener Composting

Heat-related illnesses are preventable. Learn the symptoms and what to do if you or a loved one shows signs of having a heat-related illness.