UCCE Master Gardeners of Riverside County

Desert Events & Updates

April 2023

What to Plant in April

Plant Seed

• Beets carrots, Chinese cabbage, lettuce, radish, turnips
• Below 2000 ft: corn, lima beans, melons, potatoes, pumpkins, snap beans, summer squash, winter squash (marginal – only if weather has warmed). Marigold, zinnia, sunflower (if weather is warm), alyssum.

Plant Seed - Greenhouse or Cold Frame 

• Above 2000 ft: melons, peppers, pumpkins, summer squash, tomatoes. Marigold, zinnia

Set out Plants

• Gladiolus
• Below 2000 ft.: parsley, peppers, strawberries, melons, squash tomatoes, citrus, dahlias.
• Above 2000 ft.: cabbage family, parsley, strawberries.

Flowers

• Last chance to plant pansies, violas and primroses.
• Make a last planting of summer bulbs.
• Set out perennials.
• Many annuals may be seeds at elevations up to 1500 ft.

Vegetables

• Transplant tomatoes, eggplant and peppers as temperatures warm.
• At cooler elevations, transplant lettuce cabbage family, collards and kale.
• After danger of frost, plant cilantro and two week intervals for a steady supply.

Lawns

• Seed and renovate lawns

Trees and Shrubs

• Last chance for planting citrus trees.
• Weather permitting, frost-tender plants can go outside now.

Maintenance

• Pinch chrysanthemums back to 6 inches every month through July.
• Trim dead flowers but not leaves, from spring bulbs.
• Mulch cane berries, cut out all old canes and reset new canes in twine.
• Cultivate and pull weed seedling now to prevent bloom.
• Check irrigation system and perform maintenance as needed.
• Check hoses as needed for fire protection.
• Prune apples, pears, any shoot tips with powdery mildew or fireblight; azaleas, rhododendrons, flowering fruit trees after bloom if needed, spring flowering shrubs, frost-damaged growth.
• Mow or cultivate grass around orchards to discourage thrips and plant bugs. Best time for cleft graphing.
• Control slugs, snails and earwigs with traps or barriers.
• Thoroughly clean debris from ponds, fountains and bird baths.

Fertilize

• Deciduous fruit trees and young shade trees at first leaves if not done in March.
• Azaleas, rhododendrons after flowering.
• Apply chelated iron to azaleas, gardenias and camellias if leaves are yellowing between the veins.
• Cool season turf grass.
• Cane berries, strawberries and strawberries
• Citrus are heavy nitrogen feeders. Mature trees need 1 ½ lbs. N per year. Divide this amount by 4 and apply each quarter one month apart for 4 months, beginning in March.
• Fertilize shrubs and trees once during spring with slow-release fertilizer.
• Fertilize bulbs after bloom.



Spray

• Pears, except Comice – weak copper spray when in bloom, one to three applications for fireblight.
• Stone fruit (below 2000 ft) – Benlate, Capton, Rubigan or Rally if rainy. Wet weathers favors brown rot.
• Stone fruit (above 2000ft.) - fixed copper when buds are swollen and starting to show first color to control brown rot, peach leaf curl, pseudomonas, blossom and canker infections.
• Grapes – treat with sulfur or other fungicide when shoots are 2” to 6” long. Continue every 7-10 days until fruit start to color.
• Apples (above 2000 ft) - for apple scab use Capton, Benlate, Rubigan or Rally when apple buds first show signs of green and repeat spray every 10 days until bloom where scab is a problem. In many cases this treatment may be combined with February insect controls. (note: Rubigan and Rally are expensive).
• Check roses for black spot, mildew and rust and spray if needed
• Check roses for aphids; control with a strong spray of water or insecticidal soap.



Growing Your Own Vegetables

Ocotillo (Fouquieria splendens) are one of easiest plants to identify in the desert. They are a large shrub with long cane-like unbranched spiny stems that grow from a short trunk. Small 2 inch leaves will grow from the stems when there is enough moisture. Dense clusters of red tubular flowers grow from the end of the stems from March through June. Ocotillo

Yellow nutsedge (Cyperus esculentus)

• Yellow nutsedge is a perennial weed in the sedge family and superficially resembles grass. Nutsedges are among the most noxious weeds of agriculture in temperate to tropical zones worldwide. More Info The ability of Yellow Nutsedge to reproduce through rhizomes, tubers and viable seeds enables it to spread rapidly and to maintain a competitive edge. In lawns, the differences in its color and texture of the leaves make it conspicuous, especially when they are growing in scattered clumps. The shoots of Yellow Nutsedge often grow faster than most turfgrasses after being mowed, causing them to stick out. Integrated Pest Management

State ban on watering ornamental grass remains in effect:

• Irrigation of non-functional turf is prohibited at commercial, industrial and institutional sites including HOAs.
• Non-functional/ornamental means turf that is solely decorative. It does not include areas that are used for recreation or civic community events or turf areas with trees.
• Fines up to $500 per day may be imposed.  

Drought Updates

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

PALM SPRINGS 

Saturday, April 1, 15 & 29 - 8am - 1:00 pm

2300 E. Baristo Rd, Palm Springs, CA, 92262

PALM DESERT 

Sunday April 23 - 8am - 1:00 pm

72559 Hwy 111, Palm Desert, CA 92260

Corona - Saturday, April 1, from 8:30 am to 12:30 pm, at Corona Mall, 309 S. Main Street

Temecula Promenade Mall - Wednesdays, April 12 & 26, from 9:00 am to 1:00 pm, at 40820 Winchester Road (J.C. Penney parking lot)

Vail Ranch HQ - Tuesdays, April 4 & 18, from 9:00 am to 1:00 pm, at 32115 Temecula Parkway (Between Ross and Kohl's)

Moreno Valley - Thursday, April 13, from 8:00 am to 1:00 pm, 26520 Cactus Avenue (University Health System Medical Center)

Riverside Downtown- Saturday, April 8, from 8:00 am to 1:30 pm, Main Street between 5th & 6th

Murrieta - Sunday, April 16, from 8:30 am-1:30 pm, 2422 Village Walk Plaza (Village Walk Place Shopping Center)

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 

Recent Desert Helpline Inquiry

“We have had two Saguaros growing side-by-side for many years. One is perhaps ten feet tall and the other is about three feet. The shorter one recently started showing signs of distress. Upon examination, I saw that it was receiving water from several drip spouts placed there by my gardener. I am afraid it has root rot or another disease and I don’t want to lose such a beloved cactus.”

Desert Helpline response: Over watering is the number one cause of cactus death. A consistently over watered cactus plant will start rotting at the roots, with the rot eventually working its way from the bottom of the cactus up. And your photo clearly shows that the smaller plant is rotting from the bottom up.

Once a cactus starts rotting, whether from the middle out, bottom up, or from the top down, all the rot must be pruned off in order to save the plant. If not completely removed, the rot will continue to spread eventually killing the cactus. Unfortunately, if a cactus is rotting bottom up (or when the cactus roots are rotted) you can't excise the rot and there is little you can do to save the main plant.

The best thing to do to save any of a rotting cactus is to cut off the healthy stem piece above the rot and propagate the healthy cutting. To do so, use a sharp knife to cut just above the rotten area, then continue to cut back the cutting in 1-2 inch layers until the center is clear of any brown or rotting flesh. Whatever tool you choose to use for the cutting, it’s extremely important that it’s clean and sterile before you make any cuts. You can simply wash your pruning shears or knife with soap and water, and then dry it before starting. I also recommend washing and drying it again between each cut. Cleaning between cuts will help prevent the spreading diseased flesh and fungus spores onto the freshly cut stem piece. Once complete, allow the cutting to dry for several days until the cut end has callused over. Then dip the stem in rooting hormone and plant it into a sandy cactus soil mix.

Sunnylands, 37977 Bob Hope Dr, Rancho Mirage, CA 92270, is hosting a fun-filled Family Day celebrating the wondrous native ecosystems of the Coachella Valley desert. Toys and games, arts and crafts, guided walks, and interactive stations will be found throughout the Center & Gardens from 9:30 am to 2 pm, Sunday April 23. Free for all to enjoy. Reservations not required. Sunnylands

2^nd Annual Wild Coachella Day will take place from 9 a.m. to 1:30 p.m. on Saturday, April 29,2023 and will be held both indoors and outdoors at the UCR Palm Desert Center, 75080 Frank Sinatra Drive. Palm Desert CA 92211. This annual program is designed to cultivate knowledge about the native species in the Coachella Valley and surrounding areas as well as inspire environmental activism and a love for nature. The event will consist of brief talks on relevant subjects, such as wildlife habitat; summer hikes; insects; snakes; and more. UCR Palm Desert

75th Anniversary Diamond Jubilee, Festival of Flowers - Riverside Community Flower Show & Home Garden Tours - Saturday & Sunday, April 29 & 30, 2023 Riverside Flower Show

In-Person Information Sessions listed below are Tuesdays from 6pm-8pm:

·        April 4 – 75080 Frank Sinatra Dr, Palm Desert CA 92211

·        April 18 – 2980 Washington St, Riverside, CA 92504

·        May 2 - - 75080 Frank Sinatra Dr, Palm Desert CA 92211

·        May 16 - 2980 Washington St, Riverside, CA 92504

Info Session Link: Information Session Registration

Application Link : UC Master Gardener Application

Interested in becoming a UCCE Master Gardener of Riverside County? Becoming a UCCE Master Gardener begins with a personal commitment to education and service to the community. In order to be accepted into the UCCE Master Gardener Program and earn the title of UCCE Master Gardener, you must attend an Information Session to learn about our program, submit a written application, and complete an interview with experienced UC Master Gardeners. Feel free to contact Rosa Olaiz at rmolaiz@ucanr.edu for any questions you may have. Visit Website