Euphorbia Trigona, African Milk Tree

Got a very bright spot in your house that’s begging for a plant? Columnar euphorbia are intricate, sculptural succulents that will happily grow indoors with proper care and attention.

Light: Euphorbia are plants that want warmth; south- or west-facing windows are the best place for them inside (four or more hours of direct sun shining on the plant), though they can also be grown in very bright indirect light. Since their skin is more delicate than cactus, they may burn if placed within 18 inches of a window. Arranging them at an angle to the window will help prevent this. If you are growing them in bright indirect light, make sure the plant has excellent drainage and is kept as warm as possible.

Watering: Since these plants grow during the summer, water should be gradually increased through late spring into summer, when they can go dry without being bone dry. This means that the soil throughout the pot doesn't feel wet, but also doesn't feel crackly and chalky. Don't let them sit around bone dry during this time; shriveling is a sign they’ve been under-watered. While fertilizer is usually unnecessary, you can apply an all-purpose fertilizer at 1/4 strength during the summer months.

Water should be gradually decreased during the fall. In nature euphorbia get very little winter rainfall. During the winter they should become bone dry between watering. It is often hard to reconstitute water into a bone dry plant (as it is like a dry sponge, where water will just run off) so make sure you let your euphorbia stand in a saucer of water until it has completely sucked up the water. Continue adding water and letting the plant suck it out of the saucer until there is standing water in the saucer that isn't absorbed. You can then either dump out the saucer or put a rag / sponge / turkey baster in the saucer to absorb the extra water and remove it. Don't ever let columnar euphorbia stand in water more than 12 hours.