Plant care
African Milk Treetemperature & humidity
Euphorbia trigona
More about african milk tree
Ideal temperature for african milk tree
Aim for 18-29 C (avoid below ~7 C) (65-85 F (avoid below ~45 F)) on the thermostat and you've handled the easy part. The hard part is the half-metre around the plant: window glass that drops to near-freezing on a January night, a radiator pumping out hot dry air, a draught from an opened front door. Move the plant 30 cm and you've usually fixed the problem. Below roughly 18°C growth pauses; cold beyond that pushes it into dormancy rather than killing it outright.
Cold tolerance & winter care
African Milk Tree is comparatively hardy (USDA 9a-11b (grown as a houseplant or summer container plant in cooler zones), RHS undefined). Within that range it tolerates a cold dormant spell outdoors; outside it, grow it in a container you can move under cover or overwinter in a cool but frost-free spot. Hardiness assumes an established plant in well-drained soil — a wet, cold root zone kills far more plants than cold air alone.
Humidity for african milk tree
African Milk Tree sits happiest at around Low to average (below ~50% is fine) relative humidity. A true desert succulent that is unbothered by dry indoor air; misting, pebble trays and humidifiers are unnecessary and best avoided. Prolonged high humidity (above ~70%) with poor airflow encourages fungal spotting and stem rot, so skip terrariums and unventilated bathrooms. The usual low-humidity tell is crisp brown leaf tips and edges while the soil moisture is fine — a sign the air, not the watering, is the problem. If you need to raise it, the reliable methods are grouping plants together, standing the pot on a tray of damp pebbles (the pot above the waterline, never in it), or running a small humidifier in winter when indoor heating dries the air most. Misting is the least effective — it raises humidity for minutes, not hours.
African Milk Tree temperature & humidity — frequently asked questions
What temperature is best for african milk tree?
African Milk Tree grows best between 18-29 C (avoid below ~7 C) (65-85 F (avoid below ~45 F)). Keep it out of cold draughts, off freezing windowsills in winter, and away from the hot dry air directly above radiators — the extremes matter far more than the average room temperature.
How cold can african milk tree tolerate?
African Milk Tree starts to suffer below roughly 18°C. It tolerates a cold dormant period within USDA 9a-11b (grown as a houseplant or summer container plant in cooler zones), but a wet cold root zone is more dangerous than cold air.
What humidity does african milk tree need?
African Milk Tree prefers about Low to average (below ~50% is fine) relative humidity. A true desert succulent that is unbothered by dry indoor air; misting, pebble trays and humidifiers are unnecessary and best avoided. Prolonged high humidity (above ~70%) with poor airflow encourages fungal spotting and stem rot, so skip terrariums and unventilated bathrooms.
How do I raise humidity for african milk tree?
Group it with other plants, stand the pot on a tray of damp pebbles (kept above the waterline), or run a small humidifier in winter. Misting only helps for a few minutes, so it is the weakest option for a plant that genuinely needs more humidity.
Can african milk tree live outside?
African Milk Tree is rated for USDA zone 9a-11b (grown as a houseplant or summer container plant in cooler zones). Within that range it can stay outdoors; outside it, grow it in a moveable container and protect the roots from a wet, cold winter.
More african milk tree care
In the UK? Keeping african milk tree warm in a UK home covers the radiator, single-glazing and heating-season humidity angle. Temperature and humidity are one piece. See the full african milk tree care guide, its cold-hardiness guide, and watering schedule — humidity and watering problems are easy to confuse.