How to Grow and Care for African Milk Tree

The African milk tree (Euphorbia trigona) is native to Central Africa. This plant looks a lot like a cactus—hence its nicknames: candelabra cactus, cathedral cactus, friendship cactus, and good luck cactus—but it is actually a succulent plant. African milk trees have triangular stems with three distinct sides seamed with ridges. The ridges are peppered with thorns and teardrop-shaped leaves. This plant stays lush and green throughout its growing season, with new growth sprouting a light green hue.

Like a cactus, the African milk tree is a long-lived plant that grows vigorously, approximately 1 to 2 feet a year up to 9 feet tall. It is often grown as a hedge due to its rapid and enthusiastic growth. When grown indoors, this plant will only grow to about half of its maximum height. African milk tree has many benefits, including being low-maintenance, purifying the air, and has several medicinal qualities such as aiding in muscle swelling and ear pain, allergies, and reducing inflammation from psoriasis.1

Like all Euphorbia (spurges), the African milk tree is toxic to humans and pets.23

Common Name	African milk tree, African milk bush
Botanical Name	Euphorbia trigona
Family	Euphorbiaceae
Plant Type	Succulent
Mature Size	6-9 ft. tall, 1-2 ft. wide
Sun Exposure	Partial
Soil Type	Loamy, well-drained
Soil pH	Neutral
Bloom Time	Spring, summer
Flower Color	White
Hardiness Zones	9-11 (USDA)
Native Areas	Africa
Toxicity	Toxic to humans, toxic to pets23

African Milk Tree Care

Here are the main care requirements for growing an African milk tree: 

• Give it a spot with bright indirect light indoors or in partial sun outdoors.
• Make sure the soil has excellent drainage.
• Water it sparingly.
• Avoid exposing it to temperatures below 50 degrees F.
• Fertilize it monthly in the spring and summer.
• Prune it to prevent it from getting top-heavy.

 

Light

African milk tree likes bright, indirect sunlight. A southern-facing window works well for indoor growing, as does an outdoor spot that receives partial sun. An area that receives full sun is suitable, as long as the summers are not consistently hot. In this instance, extra watering may be needed to offset the hot, bright sunlight. If your growing environment experiences hot summers, locate the plant in a spot with partial shade to avoid overheating.

Soil

This succulent isn’t fussy about its soil. Still, good drainage conditions are essential. Amend heavy clay soil for proper drainage or it may hamper the plant’s growth. Sandy and sandy loam soils help this plant thrive in a xeriscape environment. African milk tree grows best with a soil pH of 6.1 to 7.8.

Water

African milk tree doesn’t need much water. This plant is drought-tolerant and useful in climates requiring xeriscaping techniques, however, you should increase the amount of water during the summer when the plant is actively growing. In winter, only provide water to the top inch of soil when it feels dry. Consider supplemental watering only if you’re experiencing bad drought conditions. Otherwise, your region’s normal rainfall should be sufficient. Water indoor plants moderately once a week, but be sure to let the soil dry out between each watering to mimic its natural habitat.

Temperature and Humidity

African milk tree prefers daytime temperatures of 65 to 85 degrees Fahrenheit and nighttime temperatures of 60 to 70 degrees Fahrenheit. They cannot cold temperatures, especially frost, for long periods of time, and should not be in temperatures below 45 degrees Fahrenheit.

Only North American gardeners in states with arid climates—where the temperatures at night stay above 50 degrees F (parts of Texas, California, Florida, and Arizona)—can grow African milk tree outdoors. This drought-tolerant plant enjoys a dry, arid climate and withstands fairly hot temperatures, but struggles in a humid climate.

Fertilizer

In the spring and summer during the plant’s growing season, treat your African milk tree to a monthly feeding of half-strength diluted water-soluble fertilizer. Do not feed it during its dormancy period in the fall and winter.

Types of African Milk Tree

There is one variety of the African milk tree, Euphorbia trigona f. rubra, also referred to as ‘Royal Red’. It has striking maroon or vibrant red leaves.

Pruning

African milk tree grows very tall and has a comparatively small and shallow root system. For this reason, older plants may become top-heavy, or even topple over, making pruning a necessity. When pruning, always wear gloves and use a sharp and sterilized knife to remove stems. The cut you create will dry over and make a callus on its own. Take care to keep the plant balanced on both sides to avoid a lopsided load on one side that may pull the plant out of the ground.

Propagating African Milk Tree

African milk tree propagates easily from stem cuttings and air layerings. Due to the plant’s toxicity, use proper protective gear when propagating—like heavy gloves—and wash your hands immediately if you get the milky sap on your skin.

Propagating by Cuttings

First, gather a sharp knife or hand pruners, alcohol wipes, a 4-inch container with potting medium, and coarse gravel. Sterilize the blades of your knife or scissors with alcohol, and then cut off one of the plant’s “arms” at its base. Rinse the arm with cold running water until it stops oozing and allow it to dry on a paper towel, out of direct sunlight, for five to seven days (this will help the tip to callus over). Once the callus has formed, plant the arm in your container so that the end sits about an inch below the soil.

Add a layer of gravel on top of the soil to help keep the cutting upright, then place the pot in a warm area with sufficient light and a temperature between 65 and 75 F, but out of direct sunlight. The cutting should root within two months. As soon as you see root growth, transplant the plant into a slightly larger, 6-inch pot.

Propagating by Air Layering

Less common than stem cutting, propagating African milk tree by air layering requires more patience, but gives a bigger plant. First, choose a healthy, thick stem that is still attached to the plant and make a clean cut halfway through with a sharp blade. (Try for a diagonal cut to keep moisture from pooling. Next, wrap the cutting with moist sphagnum moss followed by plastic wrap to maintain the humidity. Expect roots in about 6 to 10 weeks, but when you notice a root ball, snip the stem below the roots and pot it in a draining soil mix. Water lightly as the plant starts to grow.

Potting and Repotting African Milk Tree

Providing ample drainage and not overwatering are important considerations when potting African milk tree. This succulent will do best in a porous clay pot that absorbs excess water. Sandy soil or potting mix formulated specifically for succulents allows for the best water drainage, especially when pumice or perlite is mixed in. Repot the plant every year or two as it continues to grow taller. This will ensure that there’s enough room for the roots to hold it in place (with a little help from stakes).

Overwintering

African milk trees won’t survive the cold. They typically won’t flourish in temperatures below 50 degrees F, so it’s important to plant them in the ground only if your climate allows. Potted plants need to be brought indoors when temperatures drop. Place your succulent in a room with good air circulation to cut down the humidity and set it in a brightly lit window with indirect sunlight.

Common Pests & Diseases

A healthy African milk tree is usually not susceptible to pests or diseases. However, watch for the cotton-like threads made by mealybugs. To remove them, mix a solution of water and a few drops of mild dish detergent, then wipe the bugs off with a cloth dipped in this solution. You can also use a paper towel and rubbing alcohol to remove bugs or spray off the bugs with water from a garden hose.

Overwatering your plant can cause fungal problems, such as cork disease, where the stems develop cork-like patches. Try saving the plant by cutting off the infected stems. Yellowing or browning of the succulent may also indicate root rot from overwatering. In this case, you will likely need to dispose of your plant entirely.

Common Problems

One of the most common problems with African milk tree is overwatering and under-watering the plant. Doing so can cause yellow and wilted leaves. yellowing leaves. Preventing this issue is much easier than remedying it, so make sure your plant is located in a warm area, and water it just enough so that the soil dries out in between waterings, but is not consistently dry.