A desert garden does best in U.S. Department of Agriculture plant hardiness zones 7 through 10. The types of drought-tolerant plants used in this style garden must be able to survive the long, hot and dry summers typical in the desert. If you choose the right plants, a great number of them will not only survive, but thrive, providing beauty and interest to your landscape.
When creating a desert garden, first consider the soil. Desert soils are alkaline, but native desert plants are adapted to desert soils and do not require any additional amendments. To prepare the soil before planting natives or desert-adapted plants, break it up to a depth of at least 8 inches and remove any rocks. Use the same soil to backfill planting holes.
Cacti are probably the first plants that spring to mind when you think of a desert garden. They are low-maintenance and lend an architectural beauty to the landscape.
Among the many varieties to choose from, golden barrel cactus (echinocactus grusonii), USDA zones 9a to 12b; Mexican fence post cactus (pachycereus marginatus), USDA zones 9b to 11b; and Santa Rita prickly pear (opuntia santa-rita), USDA zones 7a to 11b, are just a few of the most popular. The golden barrel cactus grows to 1 to 3 feet and is effective as a mass planting. Mexican fence post cactus, growing 2 to 6 feet wide and 5 to 12 feet tall, makes a nice specimen. And with its purple-colored pads, Santa Rita prickly pear -- 2 to 6 feet tall and spreading up to 8 feet -- also bears bright blooms and edible fruit.
Along with cacti, agaves add a striking sculptural element to the desert garden. Ranging in size from manageable at maturity -- 1 to 2 feet for a thread leaf agave (agave filifera), USDA zones 8b to 11b -- to imposing, such as the octopus agave (agave villmoriana), USDA zones 9a to 11b, which grows to a height and width of up to 5 feet, they also make fine container specimens.
There are a number of large desert trees that provide much-needed shade for gardens and homes. Among the more well-known, the mesquite tree (prosopis spp.), can grow and spread up to 30 feet, so give it plenty of room. USDA hardiness zones vary with the species.
Palo verde trees (Parkinsonia spp.), valued in the desert garden for unusual green bark, bloom with bright yellow flowers in the spring. Parkinsonia x 'Desert Museum' grows to a height and width of 25 to 30 feet and is hardy in USDA zones 8a to 9b.
Leucophyllum frutescens 'Compacta', USDA zones 9a to 11b, attracts butterflies with lavender flowers during the growing season while reaching 3 to 7 feet all around.
With crepe-y white blooms from spring into fall, Texas olive is hardy throughout USDA zones 9a to 10b.
Perennials, Groundcovers and Vines
Irrigation and Mulch
Although drought-tolerant, desert-adapted plants, especially newly planted ones, do require water. Drip irrigation delivers water directly to the root zone of the plant, benefiting the plant while conserving water.
Mulch is crucial in the garden. It keeps warmth in the soil during cold periods, shades roots in the summer, suppresses weeds and helps to conserve moisture. Rock mulches used in desert gardens include decorative rock, decomposed granite and gravel.