Euphorbia trigona (African milk tree): care and toxicity

To care for an Euphorbia trigona, place it in front of your brightest window, plant it in cactus potting mix amended with gravel, water thoroughly only when the surface has dried, and keep it almost dry and frost-free in winter.

Nicknamed the African milk tree or candelabra cactus, Euphorbia trigona is not actually a cactus: it is a euphorbia, and even the smallest wound releases an irritating white latex. This guide draws on Kew, the RHS (Royal Horticultural Society) and NC State Extension (North Carolina State University’s extension service).

You’ll find advice on light, watering, staking the columns, safe propagation, diagnosis and precautions when handling the latex. For the basics that apply to all succulents, see our cactus and succulent guide.

🌿 Why choose an African milk tree?

Euphorbia trigona brings a rare graphic verticality: its green columns marbled with pale bands branch out like a candelabra and eventually form a small living sculpture. According to the RHS, it reaches 2.5 to 4 m tall and just 0.5 to 1 m wide in 10 to 20 years: slow growth that keeps it at living-room scale for a long time.

It is a succulent from a seasonally dry tropical biome (Kew): it tolerates the dry air in our homes and forgives a missed watering. The trade-off is well known: irritating latex and spines, which call for a carefully chosen spot.

🔎 Euphorbia trigona at a glance

According to Kew (Plants of the World Online, Euphorbia trigona), the accepted name is Euphorbia trigona Mill., published by Philip Miller in 1768, in the Euphorbiaceae family. It is a succulent shrub or tree whose native range extends from Gabon to Malawi (Angola, Congo, Democratic Republic of the Congo, Gabon, Malawi), in the seasonally dry tropical biome.

The epithet trigona means “three-angled,” referring to its triangular stems, notes NC State Extension. Its teardrop-shaped leaves are about 5 to 10 cm (2 to 4 inches) long and fall seasonally.

The RHS profile rates it H2 and gives its mature height as 2.5 to 4 m.

📋 Quick care guide

Essential growing guidelines, all in one place.

📍 Where to place an Euphorbia trigona and when to move it outdoors

Place Euphorbia trigona as close as possible to a bright window: the RHS recommends anything from full sun to partial shade, with a south-, west- or east-facing aspect. NC State Extension recommends bright light indoors and, outdoors, a spot in partial shade that receives 2 to 6 hours of direct sun per day. Away from the window, new growth becomes thin and bends toward the light.

Also choose a spot away from walkways: its spines and latex make it a poor fit for a narrow hallway or children’s play area.

📍 Ideal location: in front of a large window or a south-, west- or east-facing window, away from walkways; a large, heavy pot placed on the floor is more stable than a piece of furniture.

🕰️ Summer outdoors: from late spring to early fall, it can enjoy a sheltered patio. Gradually acclimate its stems to direct sunlight to prevent scorching.

🌳 Indoors or outdoors: in France, grow it in a pot and bring it indoors before nighttime temperatures fall below about 7 °C (45 °F), as NC State advises; planting it in the ground is only an option in frost-free climates (USDA zones 9a to 11b).

🪴 How to repot an Euphorbia trigona without getting hurt

The RHS guide to indoor cacti and succulents recommends peat-free cactus potting mix, or John Innes No. 2 potting mix amended with up to 30% fine gravel.

Repot in spring, only when the plant has outgrown its pot: an oversized volume of soil stays damp and encourages rot. For a tall column, choose a heavy terracotta pot to lower the center of gravity. Before you start, put on thick gloves and goggles: even a broken stem releases latex.

columns: 4
columns_mobile: 2

✂️ Everyday Euphorbia trigona care

Caring for Euphorbia trigona comes down to watering and stability. The RHS recommends watering thoroughly as soon as the surface of the potting mix feels dry, allowing any excess to drain away; NC State Extension advises waiting until the soil is dry 2.5 to 5 cm (1 to 2 inches) deep.

Over the years, the columns become heavy: a stake and a stable pot help prevent them from toppling or breaking.

💧 Watering: Push a finger into the potting mix: if it is dry a few centimeters down, water until it drains out, then empty the saucer.

🌱 Fertilizer: Once a month from April to September, using a potassium-rich liquid fertilizer or one formulated for cacti (RHS); none in winter.

🪢 Staking: As soon as a column becomes heavy or starts to lean, secure the main columns to a rigid stake without tightening it or damaging the skin.

✂️ Pruning: If it gets too tall, the RHS recommends cutting it back in early spring; make a clean cut while wearing gloves and goggles, and save the sections for propagation.

👀 Monitoring: Inspect the base of the spines and leaves: mealybugs (RHS), aphids and spider mites (NC State) are the pests to watch for.

🍂 Watering Euphorbia trigona through the seasons

In spring and summer, during the growing season, water thoroughly whenever the surface of the potting mix has dried; don’t follow a fixed schedule, as watering frequency depends on light, heat and pot size. The RHS guide recommends watering as little as possible from November to early March, only enough to prevent the plant from shriveling.

For indoor cacti and succulents at rest, the same RHS guide recommends nighttime temperatures of around 8 to 10 °C; for Euphorbia trigona, NC State sets a lower limit of about 7 °C (45 °F) that should not be crossed. A bright, temperate room away from a radiator that dries it out abruptly suits it well.

📅 Seasonal care calendar

🌱 How to propagate Euphorbia trigona safely

The RHS recommends taking cuttings in spring or early summer and dipping the cut end in charcoal or warm water to stop the latex flowing. Wear gloves and goggles, make a clean cut through a side branch at a narrow point, then rinse the wound on the parent plant with warm water.

Leave the cutting in the shade to dry until it forms a callus: the RHS advises one day to a week for succulents, and a little longer for a thick stem. Then place it in barely moist cactus potting mix, staking it if it is tall. NC State also mentions air layering.

For advice on both methods, see propagating in water or potting mix.

🐛 Common problems: causes and solutions

An Euphorbia trigona in trouble is almost always reacting to watering, light or cold. Here are the most common symptoms, their causes as documented by the RHS and NC State Extension, and what to do about them.

🌸 Our varieties of columnar euphorbias

Here are the documented forms of Euphorbia trigona and related columnar euphorbias in our catalog. Please note: our plants are sold under the trade name “Euphorbia eritrea, African milk tree” (originating in Eritrea and Ethiopia, according to our product listing). This name suggests Euphorbia erythraeae, which Kew classifies as a synonym of Euphorbia abyssinica, a species distinct from E. trigona and native to northeastern Africa (from Sudan to Somalia, including Eritrea). The growth habit and cultivation are similar, but these are not Euphorbia trigona.

🎨 What plants pair well with Euphorbia trigona?

Euphorbia trigona pairs well with plants that like sunshine and infrequent watering. The jade plant (Crassula ovata) shares its sunny windowsill and low-water routine, with a more rounded silhouette. Sansevieria offers a similarly upright look with flat leaves and tolerates less brightly lit corners better.

Group them in terracotta pots, and explore our cacti and succulents, large and medium-sized plants, and easy-care plants.

⚠️ Is Euphorbia trigona toxic to people, cats, and dogs?

Yes. The RHS notes that it is irritating to the skin and eyes and harmful if swallowed, and recommends wearing gloves and protective equipment when handling it. NC State Extension rates it as moderately toxic: the latex can cause skin irritation, rashes, and blisters, as well as severe eye irritation; if ingested, it can cause severe gastroenteritis, vomiting, diarrhea, and convulsions.

The toxic substance identified is a group of diterpene esters (euphorbol esters); the parts involved are the stems, leaves, roots, and latex.

The ASPCA (American Society for the Prevention of Cruelty to Animals) does not have a dedicated entry for E. trigona; its Pencil Cactus entry covers another euphorbia, E. tirucalli, which is classified as toxic to dogs, cats, and horses because of its irritating sap (mouth and stomach irritation, sometimes vomiting, although the ASPCA considers its toxicity to be often overstated).

If sap gets in your eye, rinse thoroughly with clean water and seek medical advice; if an animal ingests it, call your veterinarian. For a room shared with a dog, see our non-toxic plants for dogs.

✅ Our expert tips for success

Growing a Euphorbia trigona successfully comes down to four things: plenty of light, cactus potting mix amended with gravel, watering only when the substrate is dry, and keeping it frost-free and almost dry in winter. If anything seems wrong, first check that the base of the stems is firm (watering), then look at the size of the new growth (light).

And always keep gloves and safety glasses handy: it is the latex, far more than the growing process, that requires caution.