Ocotillo is quite drought tolerant, but not for the usual reasons. These succulents are mysterious. They lack the usual succulent leaves and stems. Nor do they have the extensive root systems one sees in some succulents and cacti. Instead, these species have found other ways to cope with dry weather. They simply shed their foliage when dry weather comes. By this unusual approach, the plants reduce the moisture that would normally be lost through the foliage during droughts.
Until the rain comes, ocotillo (Fouquieria splendens) remains in this inactive state. At the first sign or rain, new foliage begins to appear. When necessary, the plants will repeat this process several times a year.
These deciduous, tree-like, shrubs can reach 5 to 20 feet in height with an equal spread. They have a swollen base. In addition, they have thorny stems. Depending on the amount of rainfall, they may be green with blotches or tan with stripes.
Why would a gardener want to grow these plant? The clue lies in the specific Latin name, splendens. This refers to the brilliant tubular red blooms. These appear in foot-long clusters. Blooming in spring and early summer, these flowers are especially attractive to hummingbirds. Their other common names include coach-whip.
This native to desert areas of the Southwest and adjacent areas in Mexico.
They are hardy only in warm areas, USDA zones 8 through 10.
Given a soil with perfect drainage and full sun, the plants should thrive. In the wild, they may be slow-growing. But in a garden setting they need more water than other succulents. If they receive adequate water and fertilizer, they have a faster growth rate. Once the plants reach mature size, be careful about overwatering.
Ocotillo can be used to create hedges. They’re also grown as specimen plants. In addition, the ones with tuberous roots are sometimes trained as bonsai.
Related species include Fouquieria macdougalii. This one is not considered to be as attractive, but is similar in overall size. It can bloom most any time. The cream white flowers are bell-shaped flowers. Fouquieria columnaris is known as the boojum tree. This is sometimes cultivated.
Some species of Fouquieria have very few spines.