5 Keys to Gardening in the Desert Southwest
Low-desert dwellers can enjoy year-round puttering in the garden, with just about any vegetable and flower thriving here. Although growing conditions may seem daunting at first glance—especially to new residents moving from regions with “real” soil—understanding and incorporating these simple techniques will turn you into a seasoned desert gardener in no time.
By Cathy Cromell
1. Know What to Plant When
The low desert offers two major growing seasons, with different annuals thriving in each. (An “annual” is a plant whose life cycle—vegetative growth, bloom, seed set—is completed in a single growing season.) Our long and leisurely cool-growing season runs seven to eight months. Sowing may start as early as mid-August, although it is common to wait until heat abates in mid- to late September. Many cool-season annuals can be sown or transplanted through February, with plants producing through April.
Warm-season sowing or transplanting begins in mid-February, and depending on the variety, may continue into June or July. Some warm-season plants will brave summer’s heat with extra water and a bit of afternoon shade. See University of Arizona Cooperative Extension’s “Vegetable Planting Calendar for Maricopa County” (extension.arizona.edu) and a “Flower and Bedding Plant Guide for the Low Desert” (cals.arizona.edu) for more information.
2. Understand Soil Conditions
Native plants are adapted to desert soil and require no amendments. However, non-native veggies and flowers need organically rich soil, and ours contain less than half of 1% organic matter. To help your soil along, incorporate 4 to 6 inches of compost or well-aged manure into garden beds before each growing season.
3. Water Efficiently
Water the soil, not the foliage. With each application, allow water to soak 10 to 12 inches deep via drip irrigation, soaker hoses or a trickling hose. Do not use lawn sprinklers or sprinkle overhead with hoses or watering cans. Splashing water on foliage spreads fungal diseases and causes salt burn as water evaporates. Overhead spraying also loses water to evaporation.
4. Mulch, Mulch, Mulch
In the garden, mulch is a powerhouse. It maintains soil moisture, moderates soil temperatures, inhibits weeds and reduces erosion. As organic mulch (any combination of compost, dried leaves, grass clippings, pine needles, straw) decomposes, it adds nutrients to the soil. Spread an inch or two of mulch on top of the entire bed or around plants, and make sure to keep it from touching plant stems.
5. Practice Organic Pest Control
Insects are an integral part of the ecosystem, and some are bound to munch at the salad bar you spread before them. Monitor plants for signs of damage. For example, irregular chewed holes or leaf edges are caused by common caterpillars such as cabbage loopers and tomato hornworms; sap-sucking aphids leave telltale sticky “honeydew” residue. With regular attention, it is possible to control critter populations with non-chemical methods such as handpicking or a forceful spray of water. Also, birds and beneficial predator insects (green lacewings, lady beetles, assassin bugs and many more) will soon arrive to control undesirable insects for you.