Boojums (Fouquieria columnaris) are iconic plants that grow naturally in the Sonoran desert on the Baja peninsula, some of the gulf islands and a small population on the coast of Sonora. They are in the ocotillo family, but have a single, conical stem with numerous side branches and white flowers in late summer. They can grow to more than 50 feet tall and can live several centuries. Here in the desert southwest, they can be grown in containers or in the ground.
LIGHT
Boojums need bright light to full sun, but can tolerate 50% sun. Small plants should have shade during the hottest part of the day. Since they are winter growers, good light is more important from the months of September through May, with the plants usually losing their leaves during the hottest months of summer.
WATERING
Boojums are cool season growers, so regular watering should take place from September through May at the rate of once a week for potted plants and once every two weeks for plants in the ground. During summer, plants in the ground should not be watered at all and potted plants should be watered every two weeks. Fertilizing once a month or so only during the cool growing season, with any house plant food at half strength, will promote faster growth.
TEMPERATURES
In nature, boojums see temperatures well into the hundreds during summer. Their response to this is to go dormant, conserving water and energy for cooler times. They can easily take the high temperatures of our arid southwest. During winter, in habitat, they often see below freezing temperatures, but normally not below the mid twenties or so. In cultivation, they are tolerant of at least the low twenties, without damage, for plants larger than thumb size. Smaller plants and lower temperatures warrant frost protection.
POTS AND SOIL
A good cactus mix should always be used in potting Boojums. Good drainage is imperative and all pots should have a drainage hole. Any pot shape will work, keeping in mind that the deeper pots hold more soil and because of that will take longer to dry out. Any type of pot will also work for boojums, with clay pots drying out faster than either stoneware or plastic. Boojums seem to prefer granitic soils in nature, but in landscapes they seem to grow well in most of our native soils. Plant them in a location that is well drained (on a slope or a mound). In the ground, here in the arid southwest, growth rates of 6 inches or more per year can be attained.