Didierea madagascariensis Baill
Didierea madagascariensis is a spiny, succulent thorn-bush tree which can reach 4 to 6 meters,columnar at first, later branching. . These hardy drought-resistant plants appear as a spine-encrusted mass of branches. The thin, grayish-green strip-like, dry deciduous leaves are well protected between the large, branched spines. The flowers are inconspicuous and male and female flowers appear on separate plants.
Use a very draining but rich soil, and not too much sun. Octopus tree can take a good deal of water during active growth and should be watered only when not dormant. Keep mostly dry during its long dormancy in winter
A very unusual plant for the dry tropical or warm temperate garden.
For watering cacti, the golden rule is to make sure the soil is completely dry before watering! This will stop the roots from rotting. It is advised to always use a pot with a drainage hole so that excess water can get drained out. If kept in a sunny area, you will need to water it once every week. If it is in a semi shaded or filtered light area, you might need to water it once in 2 weeks.
Cacti like soil that is well aerated and fast draining. You can fertilise the cactus in the summer months when it is in its growing season. During the winters it is best to cut back on any fertiliser and let the plant rest.