Idria columnaris boojum tree
(This plant comes in a 3.5" pot. You will receive a very similar plant to the one in the picture. It may or may not be blooming at the time of your purchase. The plant is shipped in its pot to prevent any damage to the roots).
Origin and habitat: Mexico
Flowers appear regularly in summer.
It grows 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.
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. 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 re sprout 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 -7°C in cultivation. Seedlings may die at -5.5”C. Plants 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.
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.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz