Crown of Thorns / Christ Plant
Euphorbia milii
description
Crown of Thorns is a thorny succulent shrub that blooms freely in strong light.
benefits
- Flowering
- Suitable for containers
warnings
- Toxic to cats
- Toxic to dogs
How to care for Crown of Thorns
sunlight
Native to sunny, dry Madagascar, Crown of Thorns grows best where it receives strong light. Give it the brightest spot you have to encourage compact growth and frequent blooms.
Bright light with direct sun
A south- or west-facing window is ideal. Aim for several hours of direct sun daily, especially in winter. It can tolerate bright indirect light, but will usually stretch and flower less there. Acclimate it gradually if moving it into stronger sun.
watering
Let the potting mix dry out well between waterings. Crown of Thorns stores water in its stems and is far more likely to suffer from wet roots than from a short dry spell.
Spring - early fall
In bright, warm conditions, water thoroughly about every 1-2 weeks. Wait until the mix is dry most of the way down and the pot feels noticeably light, then soak until water drains out and empty the saucer.
Late fall - winter
When growth slows in cooler or lower light, water roughly every 2-4 weeks. Check deeper than the surface: water only when the root ball is nearly dry. Slightly soft leaves can signal thirst, but do not water on schedule alone.
humidity
Relative humidity
Native to seasonally dry Madagascar, Crown of Thorns is comfortable in average indoor air and does not need tropical humidity. It usually tolerates humidity down to about 25% if it is watered appropriately.
Very dry, heated air can contribute to crisp leaf edges, leaf drop, or spider mites, especially if the potting mix also stays dry too long. Check the soil and watering routine first rather than misting the foliage.
temperature
Preferred range
Winter minimum
Native to warm Madagascar, Crown of Thorns prefers steady warmth and is easily stressed by chill. Keep it away from cold window glass and unheated rooms in winter.
nutrition
March - September
Feed about every 4-6 weeks while the plant is actively growing or blooming, using a balanced liquid houseplant fertilizer diluted to about half strength. Stop in winter unless it is clearly putting on new growth in warm, bright conditions.
Phosphorus
Phosphorus supports root growth and flowering. A balanced fertilizer provides enough without pushing blooms at the expense of overall health.
Potassium
Potassium helps support sturdy growth and flowering, especially for plants kept in strong light.
soil
Gritty, fast-draining soil
Crown of Thorns has succulent roots that rot in dense, soggy compost. Use cactus soil or mix regular potting soil with plenty of perlite, pumice, or coarse sand so water runs through quickly.
pH 6,0 - 7,0
This is slightly acidic to neutral, a range most cactus and succulent mixes already provide. Choose a peat- or coir-based mix with mineral grit, and avoid repeatedly adding acidic amendments.