Tucson Cactus and Succulent Society Home
Events Calendar
Cactus Rescue
The TCSS Events Email List
School and Research Grant Programs
Member C&S Businesses
Pima Prickly Park
Pop-Up Tours
Tucson Plant Info
C&S Plants Database
Native C&S Plants
Sonoran Conference
Contact Us

Members-only Facebook

Public Facebook

Rescue Cacti for Sale
Tucson Cactus and Succulent Society

Growing Succulents in the Desert Column, April 2010

(List of Growing Succulents in the Desert columns)

Ocotillo: Guaranteed to Flower in April

By Mark Dimmitt

(This article may only be reprinted with the author's permission.)

Ocotillo (Fouquieria splendens, Figure 1) is one of the most distinctive shrubs in the desert Southwest. Nothing else can be mistaken for it. It occurs in all three warm North American deserts. (The Great Basin Desert is too cold for it.) The species ranges from western Texas to the desert’s edge in California, and from the base of the Mogollon Rim in Arizona to central Sonora and the central Baja California Peninsula. There is also a population in the Grand Canyon. The species is one of only 11 in the genus, which in turn is the only genus in the family Fouquieriaceae. The family has no close relatives.

Ocotillo is one of a tiny handful of our regional plants that flower every year without fail. They flower even after a year with no biologically effective rain events (roughly 0.2 inches). In 2002-2003 Tucson suffered a 13 month period with no rain over a quarter-inch. Ocotillos were the only plant that flowered well. Even prickly pears failed to bloom that spring, and the saguaro flowering was very sparse. Moreover, the flowering time is also very consistent. Around Tucson the bulk of the population flowers throughout the month of April. To the west and south, where it gets warmer earlier, they flower a month or more sooner.

The spikes of beautiful bright red to red-orange flowers (Figure 2) borne at the tips of the long, mostly unbranched canes look like little torches, and some say that’s the source of the common name. The word ocote applies to numerous species of pine tree, the pitch of which is used for torches. Ocotillo is the diminutive form of the word. The red-tipped stems do indeed look like little torches. Other sources say that the word means a coachwhip, also an apt name.

Is ocotillo a succulent? This author says yes, definitely. The plant has all the traits of a succulent except for swollen stems or leaves. They have widespread, very shallow root systems that can take up water after very light rains. They can also respond quickly to rain. Ocotillos are leafless during dry seasons (Figure 3). New leaves can be seen emerging from the stems just 24 hours after a summer rain, and will be fully expanded in about 5 days (Figure 4). This rapid response requires something that only succulents possess – idling metabolism. Nonsucculents such as creosotebush take a couple of weeks to resume full growth from their dormant condition. Succulents are never completely dormant; they maintain a low level of metabolism all year. Like an idling car that can rev up to full speed much faster than one that has been turned off over a subzero night, succulents can leap into full growth very quickly. The idling tissue in ocotillo is apparently the thin layer of green tissue just below the bark (Figure 3).

Ocotillos can produce two or more crops of leaves per year. After a wet winter, they leaf out when weather warms in spring (as early as January in the low desert, March in Tucson). They shed the leaves during the foresummer drought, then leaf out again with the summer rains. The leaves turn yellow and drop a couple of weeks after the last rain. At higher elevations or late autumn in the desert, colder nights cause the leaves to turn orange before falling (Figure 5). Plants at higher elevations also often flower again in the late summer or fall. The population in Texas Canyon east of Benson is an example.

Hummingbirds are the primary pollinator in most ocotillo populations. In dry years ocotillo flowers are almost their only food source as they migrate into or through the Sonoran Desert in spring. The flowers are also pollinated by carpenter bees. Although these bees “cheat” by chewing holes in the bases of the flower tubes to get at the nectar, they still pick up pollen while crawling on the inflorescences. In the eastern part of ocotillo’s range in Texas where there are few hummingbirds, carpenter bees are the main pollinator. The flower tubes are shorter there, and the bees don’t have to cheat. Other animals such as verdins and woodpeckers steal nectar by poking holes in the flower bases; they are probably not effective pollinators.

Ocotillos are easy to transplant, whether leafy or bare. It is crucial to excavate about a foot of each lateral root without breaking it. Plants from the wild that have been damaged by being roughly torn from the ground, breaking off or splitting the laterals, have a high mortality. Replant at the same depth as they were originally. Plants will reestablish more quickly if the canes are sprayed with water several times a day until they leaf out. Do not water the roots heavily until there are signs of new growth.

While ocotillo is a common, widespread species, there is concern that they are being overharvested for the landscape trade. Ocotillo cane fencing is especially popular. The cut wild plants will regrow, but it takes years. Seed-grown ocotillos have recently become available, and are a greener choice for your gardens. They grow rapidly with generous watering.

Future articles will feature some of the other excellent species of Fouquieria.

List of Growing Succulents in the Desert columns