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The Triangular Spire

African Milk Tree

Euphorbia trigona

Upright angular branches and short-lived leaves give African Milk Tree its tall architectural form. Use bright light, free drainage and deliberate protection from its irritating milky sap.

Explore the care guide
Botanical illustration

Care at a glance

Light

Bright filtered or indirect light; acclimate carefully. [1]

Safety

Irritating latex and spines; protect skin and eyes. [2]

Know your plant

African Milk Tree is Euphorbia trigona, a succulent member of the spurge family. Its upright angular stems carry small leaves and paired spines along their edges. [1]

The leaves are short-lived; firm green stems remain the main framework. A few lost leaves do not, by themselves, mean that the whole plant is dying. [2]

Light and placement

Give bright indirect light indoors. For a summer outdoor position, introduce partial sun gradually and watch the newest tissue for scorch. [1]

Keep the whole branching crown well lit. Rotate a manageable pot periodically rather than letting all new growth lean strongly toward one window. [6]

Watering

  1. Let the upper 1–2 inches / 2.5–5 cm of mix dry before watering. Then wet the root ball evenly and let excess escape. [1]

  2. Empty the saucer and recheck before watering again. Lower light and cooler rooms lengthen the drying time. [10]

Soil and pot choice

Use a free-draining cactus or succulent mix. Keep drainage holes open and size the container around the roots rather than the eventual height. [2]

A stable pot is important beneath a tall crown. Maintain the stem’s former planting depth instead of burying it for extra support. [11]

Temperature and humidity

Keep African Milk Tree warm and protect it from frost. Bring outdoor containers inside before temperatures fall below 45°F / 7°C. [1]

Ventilate warm rooms and avoid cold, wet conditions. Extra humidity is unnecessary for this succulent-spurge growing approach. [4]

Feeding

Feed lightly during active growth with a diluted succulent product. Follow its directions and avoid repeated feeding to force rapid height. [9]

Stop when growth slows. If the potting mix includes a slow-release feed, account for that before adding liquid fertilizer. [18]

Repotting

  1. Wear gloves and eye protection before moving the plant. Support the root ball and crown; ask for help with a plant too large to handle securely. [5]

  2. Use a modestly larger draining pot when roots crowd the old one. Refill around the root ball at the same depth and keep the trunk upright. [17]

Propagation

  1. Take a healthy stem cutting during spring or early summer, using clean tools and skin/eye protection. Avoid contact with the sap released at the cut. [2]

  2. Let the cut dry and callus, then place its base in a small pot of draining medium. Keep moisture slight until roots form. [7]

Pruning and growth

Prune in early spring only if size or balance needs attention. Support the part being removed and make a clean cut with appropriate protective equipment. [2]

Keep cuttings and sap-contaminated debris away from children and animals. Wash tools and hands after the work. [5]

Problems and checks

Decline around the lower stems

Possible causes
  • Persistently wet roots.
Checks to distinguish them
  • Check deep moisture and trapped runoff.
Low-risk next step
Empty runoff; pause watering wet mix.
When to seek expert help
Seek advice for spreading softness.
Sources for these checks

Waterlogged roots may lose function. [8]

Stems or pads shrink

Possible causes
  • Dryness or impaired wet roots.
Checks to distinguish them
  • Check root-zone moisture before adding water.
Low-risk next step
Water dry mix; correct trapped moisture.
When to seek expert help
Seek advice if decline persists.
Sources for these checks

Appearance alone cannot determine watering need. [12]

Dry pale or tan patches after a move

Possible causes
  • Abrupt strong sun.
Checks to distinguish them
  • Compare damage with the newly exposed side.
Low-risk next step
Provide gentler light.
When to seek expert help
Seek advice for spreading damage.
Sources for these checks

Gradual exposure changes reduce scorch risk. [15]

Fine webbing with pale speckling

Possible causes
  • Possible spider mites.
Checks to distinguish them
  • Look closely at affected growth with a hand lens.
Low-risk next step
Confirm the pest before treatment.
When to seek expert help
Seek help if damage continues.
Sources for these checks

Mites can cause fine mottling and webbing. [16]

Seasonal indoor care

Retain a bright position through winter, with reduced watering as growth slows. Keep the pot away from cold drafts and avoid a wet root ball during rest. [4]

Children, pets and sap safety

Safety

The milky sap can injure skin and eyes and is harmful if swallowed. Keep the plant, cuttings and debris away from children and pets. [2]

For sap on skin, wash with soap and water. For eyes, rinse with running water for 15–20 minutes and get poison-service advice promptly. [5]

Human poisoning (U.S.): 1-800-222-1222. Medical emergencies: 911. [13]

Pet poisoning: veterinarian; ASPCA 888-426-4435 (consultation fee). [14]

Similar plants

African Milk Tree resembles a cactus but is a Euphorbia. True cacti have areoles; succulent euphorbias have a different stem structure and irritating milky latex. [4]

Sources

References checked October 5, 2026. Botanical identity, cultivation and handling guidance are linked to the sources below; general growing advice is adapted to container conditions.

  1. Euphorbia trigona

    NC State Extension

    Accessed October 5, 2026

  2. Euphorbia trigona — African milk tree

    Royal Horticultural Society

    Accessed October 5, 2026

  3. Euphorbia trigona

    National Parks Board, Singapore

    Accessed October 5, 2026 · Updated: 2026-09-17

  4. Indoor and greenhouse euphorbias

    Royal Horticultural Society

    Accessed October 5, 2026

  5. Keep away from spurge sap

    National Capital Poison Center

    Accessed October 5, 2026

  6. Growing Succulents Indoors

    Iowa State University Extension

    Accessed October 5, 2026

  7. How to Propagate Succulents

    Iowa State University Extension

    Accessed October 5, 2026

  8. Common Problems and Issues of Succulents

    Iowa State University Extension

    Accessed October 5, 2026

  9. Cacti and Succulents for the Indoors

    UC Master Gardeners of Tulare and Kings County

    Accessed October 5, 2026 · Publisher date: 2026-06-27

  10. Watering

    University of Illinois Extension

    Accessed October 5, 2026

  11. Indoor Plant Culture, 426-100

    Virginia Cooperative Extension

    Accessed October 5, 2026 · Publisher date: August 2018

  12. How to help a poorly houseplant

    Royal Horticultural Society

    Accessed October 5, 2026

  13. Need immediate assistance?

    National Capital Poison Center

    Accessed October 5, 2026

  14. ASPCA Poison Control

    ASPCA Poison Control

    Accessed October 5, 2026

  15. Excess Light on Indoor Plants

    University of Maryland Extension

    Accessed October 5, 2026 · Updated: 2023-03-13

  16. Glasshouse red spider mite

    Royal Horticultural Society

    Accessed October 5, 2026

  17. Repotting Houseplants

    Penn State Extension

    Accessed October 5, 2026 · Updated: 2026-02-23

  18. Caring for Houseplants

    University of Georgia Cooperative Extension — Lincoln County

    Accessed October 5, 2026 · Publisher date: 2022-08-31