Lantana, rosemary, Texas sagebrush and gaillardia are a few garden plants that are drought resistant once established. Most rudbeckias, perennial salvias, coreopsis and portulacas also hold up well during periods of low rainfall.
Many native wildflowers, such as penstemmons, agaves, mallows and evening primroses, are naturally adapted to drought conditions. Drought-tolerant vines and creeping plants include bougainvillea, trumpet vine and passionflower.
Sonoma County Master Gardeners in California recommend shrubs such as rockrose, oleander, mahonia and heavenly bamboo. Christmas cactus, hen and chicks, aloe vera and other succulents can go without additional water for several weeks. Pine, acacia and some species of cypress trees can survive off low annual rainfall once mature.