Spring wildflowers abound this month in the desert and possibly in your garden as well as the days warm. Pollinators, critters and
pests will all be out enjoying the bounty, making this a busy month for gardeners - so keep an eye out and take environmentally
friendly action as needed to maintain your alive and active landscape. Plant your garden with the things you enjoy most; the options
are endless.
Maintenance
- Remove any remaining winter damaged plant parts and compost them unless diseased. Flower stalks on fading spring bulbs are
not trimmed - allow them to die back naturally but when fully spent, trim at the base. - Thin fruit of deciduous trees such as apple, peach, plum and apricot. Pick marble-sized (or smaller) fruit off so that the fruit are
spaced about 6 inches part. - Protect young plants from wildlife. The best way to keep critters out is to use fencing 2’ to 3’ high. Stake the fencing to keep it
standing up. Cage individual plants or entire plantings. For rabbits, use ½” poultry wire. For ground squirrels or chipmunks, use
fencing with smaller openings; ¼” woven wire and cap the top as squirrels and chipmunks can climb. Leave fencing in place until
plants become mature & less appealing to them. - If your plants have yellowing or discolored leaves, contact the Master Gardener Plant Clinic for expert diagnosis and guidance on
how to resolve the issue. - Check your irrigation systems for leaks, clogged emitters and other issues. Regular maintenance includes flushing the lines on an
annual basis. - Monitor tender new growth on roses and other plants and check the undersides of leaves for aphids, thrips, and spider mites.
Instead of chemical controls, use a blast of water to dislodge pests or add 1 tablespoon of liquid dish detergent to 1 gallon of
water and spray the top and bottom of leaves. - Flush accumulated salts from root zones of drip-irrigated plants in containers/raised beds by watering once 3X as long as normal.
- Plan or install active or passive Water Harvesting systems before monsoon.
- Mulch to a depth of 3-4 inches around trees and shrubs. Be sure the mulch is a few inches away from the trunk; don’t make a
“mulch volcano” as you can harm the plant.
Planting
- Plant warm season annuals for summer flowering-aster, coneflower, gaillardia, lisianthus, marigold, pentas, portulaca,
Madagascar periwinkle, and zinnia. - Plant perennials that provide color and attract pollinators such as chamomile, Gooding’s verbena, justicia, lantana, Russian sage,
and salvias. - Plant summer bulbs such as dahlias, iris, and caladium.
- Sow seeds outdoors for cucumbers.
- Transplant seedlings of eggplant, squash, peppers, tomatoes, and thyme into the soil.
- Plant heat-loving vines such as Baja passion vine, pink trumpet vine, yellow orchid vine, and crossvine
- Plant fig trees.
- Plant citrus trees to give them time to get fully established before cold weather.
- It’s the perfect time to plant heat-loving herbs such as Basil, Oregano, Rosemary, Sage, Thyme and more.
- Plant cacti and agaves as well as native and non-native desert-adapted plants to allow roots to establish before the heat begins.
Consider the mature size and sun demands and any other limitations for location.
Fertilizing
- Fertilize established (not newly planted) citrus (2nd of 3 annual feedings) if you did not do so in March. For oranges, tangerines,
and grapefruit, the first application was 1/3 of the total in January or February, the current 1/3 in March or April, and the last1/3
is in May or June. - Fertilize Bermudagrass once a month.
- Begin mild fertilizing of vegetables gardens.
- Fertilize your roses on a 3 to 4 week schedule.
Watering
- As the weather warms, increase your watering frequency but adjust if your garden receives significant rainfall.
- Consider a free water efficiency audit from the City of Tucson Zanjero Program.
More Information
Pima County Master Gardener plant clinic
City of Tucson irrigation maintenance checklist
City of Tucson Zanjero Program, free water audits
Training and pruning fruit trees
Ten Steps to a Successful Vegetable Garden
Landscape Vines for Southern Arizona
Landscape management practices for passive water harvesting
Flower Planting Guide for the Low Desert
Selecting and Planting a Saguaro
Citrus Fertilization chart for Arizona
Extension Publications
For more information on any of these topics, search our database of Extension publications going back more than 100 years housed in the University of Arizona Campus Repository.