GardenWizzPlant Care Card

Crown of thorns

Euphorbia milii · Succulent

Photo: Vengolis · CC BY-SA 4.0 · cropped from original

Hardiness
H1b Subtropical, heated glasshouse (RHS profile linked: 10–15°C)
Position
Full sun
Height × Spread
?–180 cm
Soil
Peat-free loam-based potting compost with added grit; free-draining.
Flowering
January–December
Toxicity
The sap is moderately poisonous and causes irritation on contact with skin or eyes. If ingested, it causes severe stomach pain, irritation of the throat and mouth, and vomiting. It is very toxic to domesticated animals such as horses, sheep, cats and dogs. For humans it is mildly toxic and only acts as an irritant.

The Gardening Year

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F
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M
J
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🌱 Sow
🪴 Plant out
🌸 In flower

Watch out for

Mealybugs: Isolate the plant and treat infested areas with a cotton bud dipped in methylated spirits or apply an insecticidal soap.

Aphids: Spray affected areas with a strong jet of water or apply a systemic insecticide if the infestation is severe.

Root rot: Ensure well-draining compost and allow the soil to dry out between waterings; repot if necessary.

Leaf drop: Maintain consistent temperatures above 10°C and avoid moving the plant frequently or exposing it to cold drafts.

Spider mites: Increase humidity around the plant and spray with a miticide or insecticidal soap.

Full guide: gardenwizz.com/plants/euphorbia-milii© GardenWizz — UK gardening encyclopedia