Euphorbia Trigona Care: How To Grow African Milk Tree Plant

African Milk Tree cactus (Euphorbia trigona) is a tall, rugged, easy-care plant with thorns. It should come as no surprise that many people think of it as an African cactus.

Quick African Milk Tree Care Guide

  • Botanical Name: Euphorbia trigona – (yoo-FOR-bee-uh) (try-GOH-nuh)
  • Common Name(s): African Milk Tree cactus, candelabra cactus, Abyssinian Euphorbia, cathedral cactus, friendship cactus
  • Family & Origin: Euphorbaceae – West Africa
  • Growability: Easy with a slow growth rate
  • Size: Outdoors 7′-9′ | Indoors 2′-4′ feet tall
  • Light: Prefers bright light. Protect for direct sun may burn the plant.
  • Temperature: 35°-90° degrees Fahrenheit
  • Water: Keep the soil slightly moist. Do not overwater.
  • Fertilizer: Feed monthly a balanced, water-soluble fertilizer spring and summer.
  • Soil:  Well-draining succulent soil
  • Pests & Diseases: Mealybug, plant scale, root rot
  • Propagation: Stem cuttings
  • Toxicity: White milky sap is a skin irritant and poisonous. Protect eyes and mouth when handling. Wash immediately if in contact with skin. Keep pets or children away.
Euphorbia trigona - African Milk Tree - potted in rustic containers
Euphorbia trigona – African Milk Tree – potted in rustic containers – image via The Borrowed Nursery

This thorny succulent hails from West Africa where it grows wild in dense, thorny thickets.

In its natural habitat, African Cactus Milk Tree (aka: Abyssinian Euphorbia) has a variety of landscaping and gardening uses.

In the United States and other areas, it is grown as an indoor plant and used as an attractive addition to cactus and succulent gardens in warmer areas.

In this article, we will discuss the characteristics, care, and uses of this interesting plant. Read on to learn more.

Why Isn’t Euphorbia Trigona A Cactus?

The African Milk Tree are considered succulent plants even though they have leaves. Cacti (with the exception of Christmas and Easter Cactus) do not grow leaves.

The leaves of the African Milk cactus are small and short-lived.

They grow along the ridges that make up the corners of the plant’s rectangular stems. Thorns also emerge from these ridges.

The thorns grow in sets of two, and single leaves emerge from between them.

When grown outdoors, the plant may produce small white or yellow flowers. Indoors, it is unlikely to bloom.

Why Is The Trigona Called A “Milk Tree”?

The African Milk Tree plant is a member of the genus Euphorbia part of the family Euphorbaceae. All of these plants exude a poisonous white sap when cut or broken.

For this reason, it’s a good idea to keep them out of the reach of kids and pets and to keep your skin and eyes well-protected when pruning, repotting or otherwise handling the euphorbia cactus.

The sap can cause serious skin and eye irritation on contact, as well as severe gastric distress if ingested. [source]

This plant caution also holds true for the red variety Euphorbia Trigona Rubra or “Royal Red”.

Is The African Milk Tree Really A Tree?

These big succulents outdoors are tree-like. They can grow as high as nine feet, and grow in a characteristic “candelabra” shape giving them the appearance of a tree. It may also explain some of the plant‘s common names:

  • Candelabra Euphorbia
  • Euphorbia cactus
  • Candelabra cactus

You can control the plant’s growth somewhat by cutting or breaking off stems, which you can plant in their own pots, using a light, sandy soil to grow more “trees” to share with friends.

How To Propagate Euphorbia Trigona

Propagation of this hardy succulent couldn’t be easier. Visually survey your Euphorbia trigona before you begin and decide which new stems or sections you want to reduce.

Be sure to put on rubber gloves and protect your eyes with goggles, then just break or cut sections of the parent plant. Sections used for rooting should be about three or four inches in length.

Don’t Try This At Home!

In this video, an intrepid gardener shows a very daring way to take cuttings!

Although he experiences no mishaps, you can see that he puts himself in great danger of having sap drip from a very tall and vigorous plant onto his bare skin and into his eyes!

Making Euphorbia Candelabra Cactus Cuttings

Luckily, this operation turned out alright, but it’s easy to see that these plants produce copious amounts of potentially dangerous sap.

When you take cuttings, be sure to have a damp cloth on hand to wipe up weeping sap. Wear gloves, goggles and long sleeves, and be careful not to let the sap come in contact with your skin or eyes.

Read our article on Cactus Propagation here.

Once you’ve taken cuttings, lay them on paper towels, newspaper or some other disposable, absorbent material.

Allow the sections to dry out and harden off for a week in a cool, dry place, out of direct sunlight. After your cuttings have hardened off, plant them in an airy, sandy, well-draining potting soil that is not too fertile.

You needn’t worry much about pH level as Euphorbia trigona grow in acidic, neutral or alkaline soil.

Water when you plant the cuttings, keep the soil lightly moist until signs of rooting and growth appear. At this point, you can reduce watering and begin treating the cutting as an adult plant.

leaves up close of the Euphorbia cathedral cactus (euphorbia trigona)

Euphorbia Trigona Care

Once established Euphorbia trigona is an easy-care plant. It’s best to provide lots of sunlight and/or artificial light. If you’ve grown Euphorbia milli (Crown of Thorns) you’ll do fine.

These plants can do very well like Euphorbia milli Crown of Thorns and Euphorbia tithymaloides “Devil’s backbone” as houseplants year-round in medium light settings and normal household temperatures.

By gradually transitioning Euphorbia trigona to more sun you can enjoy the African milk bush in the great outdoors during the spring and summer.

Transition the plant gradually, so it acclimates to more sun, air movement and temperature fluctuations. Choose a sheltered area that gets filtered sunlight or part sunlight for potted and container plants.

If you live in a semi-tropical or desert area where temperatures will unlikely to drop below 50° degrees Fahrenheit and never freeze, plant Euphorbia trigona directly in the ground.

In this case, choose a fairly sheltered location that receives full sun or part shade.

If you need to move your Euphorbia trigona outdoors or repot as a container plant, it’s best to do so in the springtime.

You can groom the parent plant and take cuttings while making the transfer. Just like when handling the – Euphorbia Tirucalli (firestick plant) remember to wear protective gear to prevent accidental stabbings and sap contact.

Grooming is easy with Euphorbia trigona. Just break or cut off stems that don’t seem to fit in. Remove any branch that protrudes and might break off accidentally as people walk past.

If accidental contact with sap does occur, be sure to wash well immediately to avoid irritation. If sap gets in eyes, it should be flushed out with running water, and a visit to the emergency room would not be overly dramatic. [source]

Water: Because Euphorbia trigona are succulents (not cacti) they do not tolerate complete drought. But they don’t like wet soil! Keep the soil very lightly moist during the growing season (spring and summer).

So you ask – “How often do you water succulent plants?” On trigona, if the top couple of inches of soil feel dry, deep watering is in order.

Just be sure the plant does not stand in water as this can lead to rotting roots. Make sure your “clay pot” has drainage holes.

Fertilizer: Provide Euphorbia trigona with a light feeding of balanced water-soluble succulent fertilizer monthly during the spring and summer. Reduce watering and do not fertilize at all during the cooler months (fall and winter).

How To Deal With Common Pests and Disease

African Milk Tree is relatively hardy and resistant to disease and pest, as long as it is well-cared-for. Avoid waterlogging the soil and providing the plant with good sunlight and air circulation. This will go a long way toward preventing problems. Weakened Euphorbia trigona may be susceptible to:

Mealybugs

If you see cotton-like threads forming on the plant, wipe them off with a paper towel soaked in rubbing alcohol. If you have a massive infestation, wipe the mealybugs off and spray the plant with a natural insecticide, such as a Neem oil insecticide spray solution.

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Plant Scale

Scale insects: These tiny insects are covered by a nearly impenetrable brown shield. This makes it difficult to remove them.

Like the mealybug wipe them off firmly with a paper towel soaked in rubbing alcohol. If this doesn’t work, scrape them off gently with a knife blade. A Neem oil solution can be used to assure they are gone and prevent their return.

More on getting rid of scale on succulents

Fungal Infection Cork Disease

Cork disease is a fungal infection. If you see patches of cork-like material on the stem, it is an indication of overwatering and/or soil that is too rich.

If you’ve kept cuttings and have replacement plants, you are best to dispose off of the diseased plant.

If you are dead-set on saving it, prune Euphorbia trigona with a very sharp, sterilized knife or shears to completely remove the damaged areas and dispose of them in the trash (not the compost heap).

Paint the cut areas with a plant fungicide. Repot the plant into a cactus soil mix and keep it in a consistently warm and airy location.

Reduce watering. You may not be able to save the Euphorbia cactus, but keeping it dry, warm and well-ventilated will give it the best chance of survival.

Rot or Fusarium Wilt

Fusarium wilt and rot is another fungal infection that comes from the soil. If your plant displays soft, reddish patches around the base of the stem, suspect fusarium rot.

Most of the time, it is fatal and disposing of the plant, pot and all is the best solution. If you keep the container, be sure to sterilize it before using it again.

If you must save the plant, follow the steps outlined for cork disease. [source]

Hardy Euphorbia Cactus is Virtually Problem-Free

All-in-all, caring for African Milk Plant is amazingly easy. Begin by choosing a healthy plant (or cutting) with no soft spots or signs of pests.

If you acquire a potted Euphorbia trigona plant, check to be sure the root system and root ball hold the plant in the pot firmly. Make sure the plant has not been sitting in water.

If you begin with a well-cared-for plant and continue to provide it with well-draining soil that’s not too rich, lots of sunlight and an airy setting, it should grow well and provide you with lots of healthy cuttings for many years.

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