Origin and Habitat: Mexico. West-central Sonora. From about 62 mi (100 km) in the Sierra Bacha. From about 6 mi (10 km) north of El Desemboque San Ignacio north to Punta Cirio south of Puerto Libertad. Also both states in Baia California and at higher elevations on Isla Angel de In Guards in the Gulf of California.
Altitude range: 33-2,165 ft (10-660 m) above sea level.
Habitat and ecology: Rocky granitic or volcanic slopes and canyons: Sonoran desert scrub. In Sonora limited to granite substrate: especially common on north-facing slopes and toward higher elevations. Throughout the range, winter rain is dependable, summer or early autumn rain occasional. They grow intermixed with the common ocotillo Fouquieria splendens, Fouquieria diguetii, Yucca valida, cacti and succulents such as Bursera microphylla and Pachycormus discolor. Seedlings are mostly found beneath shrubs, in rock crevices, or beside rocks. Under natural conditions, the plants grow fastest 1.5-1.9 in/year (4-5 cm/year) at a height of 8.2-11.5 ft (2.5-3.5 m). Yearly measurements of height growth suggest that plants 50 ft (15 m) tall may be 500-600 years old. The flowers have a strong, sweet honeycomb fragrance and produce a noticeably sweetened nectar, and are visited by a variety of insects, including 15 species of bees as well as various beetles, ants, and butterflies as well as hummingbirds.

Cultivation and Propagation: Boojum tree (Fouquieria columnaris), superficially recalling Pachypodium lealii (Apocynaceae) from Namibia and Alluaudia procera(Didiereaceae) from Madagascar, and is equally sought by collectors
Growth rate: It is a very, very slow-growing tree, but long lived, some are thought to have achieved over 500 years of growth. Boojum trees are fairly slow growing, so they will remain happily in a container for a very long time. For maximum growth the plants need ample root space.
Dormancy: Fouquieria columnaris are summer dormant. This means that beginning sometime in April plants begin to lose their leaves and reduce metabolic activity significantly. The plant blooms during this dormancy, usually in July and August. Leaves will reappear and growth will resume sometime after mid-September, occasionally as late as November.
Soil: Needs a very well drained soil mix. Be careful that the plant is not placed in an area that accumulates water, or is in the fall of a roof drip line. The addition of gravel, decomposed granite, or sand will help loosen heavier soils, thereby allowing the root system to get spread out and established evenly. Other soil amendments are not necessary.
Transplanting: Large Boojum trees seldom survive transplanting. They are best planted in the fall, at the beginning of their growing cycle. However, a spring planting can be successful if care is given to shading the plant.
Exposure: Boojum trees grow best in full sun to part shade. Very small plants should only be planted out if they can be protected from full sun by a bush or tree as they grow up. Larger plants do best in full sun, but even then plants need shade during the first summer to avoid sunburn. Sunburn will show up as a yellowing of the skin on the south or west side of the plant. They need freely circulating air.
Watering: Watering should be greatly reduced during the lust summer months to prevent rotting. Plants are watered and allowed to dry thoroughly before watering again. In the cool weather, when the plant is actively growing, water a Boojum regularly. Small plants in pots may need water weekly. During this time, leaves which turn yellow or brown, or begin to drop are a sign of too little water. Plants in the ground, which are over 1 mt tall, do well with regular watering every 2-3 weeks during the cool season. While dormant, during the warm weather, Boojum trees require only enough water to keep them from shriveling. Leaves which turn yellow or brown and drop in late spring are a signal of the onset of dormancy, and cannot be encouraged to resprout with watering. Watch the tip; if it begins to shrivel or shrink, water the plant, otherwise it is best left alone. The onset of leaf buds, or the sudden appearance of leaves marks the end of the dormant period.
Hardiness: Cold tender. However some older, established plants have survived overnight temperatures of 19°F (-7°C) in cultivation. Seedlings may die at 23°F (-5°C). lants put in the ground should be covered when they are small, and placed in a very warm area of the yard away from cold air accumulators such as washes or depressions.
Fertilization: If fertilizer is used, it should be diluted to ¼ (one-quarter) the recommended rate on the label.
Propagation: It is readily propagated by seeds and young plants an available in the horticultural trade. In habitat most seeds germinate during the winter rain but in cultivation, they germinate readily without pretreatment. In cultivation the seedlings may grow continuously through their first year but thereafter produce stem growth only from October to April.
Bonsai culture: It can be trained as a bonsai, pinch and prune plants in spring and summer but taper off in autumn so the tree can store energy for the winter instead of using it to put on new growth before resting.
Propagation: It is propagated from cuttings taken in the spring or from seed when available.
Warning: The thorns can be hazardous.