African Milk Tree Plant Profile

closeup of african milk tree with green leaves against white wall

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African milk tree (Euphorbia trigona) is native to Central Africa. It is often grown as a hedge there, useful for its rapid and enthusiastic growth, though its roots are not invasive. Though it looks a lot like a cactus, it is actually a succulent plant. It has many folk names, including candelabra cactus, cathedral cactus, friendship cactus, good luck plant or good luck cactus (the good luck attribution is probably due to how quickly it grows, and how easily it propagates). It stays lush and green throughout its growing season, and new growth has a lighter green color than the base plant. The Rubra or Royal Red cultivar is very popular for its dramatic coloring: it takes on bright red accents later in the season.

Scientific Name Euphorbia trigona
Common Name African Milk Tree, African Milk Bush
Plant Type Succulent
Mature Size 6 to 8 feet
Sun Exposure Indirect sun to partial shade
Soil Type Medium rich, well drained
Soil pH 6.1 to 7.8 (mildly acidic to mildly alkaline)
Bloom Time Spring - summer
Flower Color White
Hardiness Zones 9b to 11
Native Areas Central Africa
Tall African milk tree in an outdoor setting.
The African milk tree can grow up to 8 feet tall,but can be easily pruned to control growth. YPM Pankreator / Flickr / CC BY 2.0 

How to Grow African Milk Tree

The African Milk Tree is long-lived and can grow very vigorously, up to two feet a year in height, to a total of eight feet tall. It is fairly easy to propagate also, similar to a cactus, where one simply breaks off one of the "arms" and roots in potting medium. They're grown by many gardeners in states with arid climates where the temperatures at night don't go below 50 degrees, such as parts of Texas, Arkansas and Arizona. It's hardy in Zones 9b through 11 in the United States, and can probably survive to Zone 8 with winter protection. African milk tree also popular as a decorative landscape or container plant throughout South America, and in the Mediterranean regions of Europe. Its dramatic size make it a sought after plant for plant enthusiasts. African milk tree is also very drought-tolerant and useful for xeriscaping. Because they grow so tall, but have a comparatively small root system, it's not unusual for them to become top heavy or to even topple over, so be sure to keep them pruned, and use staking where needed.

Light

This succulent likes indirect but bright sunlight: a southern-facing window will work well for it indoors, or an outdoor spot with partial sun. Full sun is suitable as long as the summers are not too consistently hot. Extra watering may be needed to offset too much bright sunlight.

Soil

This plant is not too fussy about soil but good drainage is essential. Heavy clay soils may hamper growth, and impede drainage. Since this plant is a good choice for xeriscaping, sandy soils are a good fit, and sandy loam probably best of all.

Water

Being a succulent, the African milk tree doesn't need much water. If there is a very bad drought, consider supplemental watering at the roots. But otherwise normal rainfall should be sufficient. Indoor specimens should be watered moderately once a week. Let the soil dry out between waterings, to mimic its natural habitat.

Temperature and Humidity

This drought-tolerant plant enjoys a dry or arid climate, and can tolerate fairly hot temperatures. It doesn't survive the cold though, and won't flourish if temperatures go below 55 F. If grown in a place with very hot summers, the plant should be located in a spot with indirect sunlight or partial shade, to avoid overheating. This plant doesn't need any extra humidity, and growing it in an environment that is too humid may cause issues such as fungus or pests.

Toxicity

The milky white sap responsible for this plant's common name is also a skin irritant, as well as an oral toxin, so handle the plant carefully and wear gloves. All parts of this plant are toxic if ingested.

Propagation

African milk tree propagates easily. You really only need a pair of scissors or hand pruners, and a container with potting medium. Use proper protective gear when propagating, like heavy gloves, and wash immediately if you get any of the milky sap on your skin. Cut one of the "arms" off with scissors, rinse with water, and plant in soil. That's it! The cutting should root within three weeks.