Areas that receive little rainfall pose particular challenges for the would-be gardener. Plants that are common in many other places will not grow in some Southwestern U.S. states, for example. However, other plants are unique to these areas because they are adapted to surviving on little moisture. If we chose native flora and water accordingly, the results can be as beautiful as what we might have achieved in places with lusher climates.
When gardening in the Southwest, it can be helpful to use Mexico as a model and choose plants that are native to the Sonoran, Chihuahuan, or Mohave deserts. Blue Century plants, Americana Agave, and Golden Barrel cacti do well here. So do flowers like desert marigolds, penstemmons, golden dyssodia, poppies, lupines, and tufted evening primroses. These plants should be situated in natural plant groupings like you would see in the desert, also. Plotting the same plants in different locations and allowing for natural spaces can promote a unified look to the landscape.
If you can manage to keep the root zones of your plants moist, they won’t need to be watered as often. Watering at night, when it’s cooler and the sun isn’t out, can be a good idea, as this allows the water to settle in without evaporating first. It should seep down about a foot for groundcovers (like grasses), two feet for shrubs, and three feet for trees. Moisten the surrounding soil a little bit, and not just the roots. For trees, this would extend slightly beyond the area beneath the ends of their branches. In a dry landscape, it’s helpful to water slowly; let it out in a trickle, and allow a longer time for it to soak in.
Many gardeners in dry areas rely on drip irrigation systems, which trickle water in beneath the soil where it’s shielded from the sun. New plants need about a gallon of water for each cubic foot of soil (minimum). Setting a drip system to two or three hours will accomplish this.
Begin by watering new plants frequently, and then slowly scale back as weeks progress. A good schedule in the summer would be to water every 1-2 days for the first two weeks, then decrease frequency to every 3-4 days for weeks 3 and 4 and finally every 5-6 days for every week thereafter until you reach the end of summer. By December, you should only need to water your plants once every two weeks to sustain them.
Many other plants can be successfully grown in dry climates, of course, not just desert-growing varieties. Vegetable gardens work fine, though they’ll require more watering than they would in other areas. Again, drip irrigation or night watering will be advantageous. Some vegetables that do well in dry areas include corn, squash, beans, and carrots and other roots. With a little extra care and preparation, this list can be expanded to include virtually anything that is grown in vegetable gardens elsewhere.