Crown of thorns Euphorbia milii
Crown of thorns (Euphorbia milii) is an evergreen perennial shrub in the Euphorbiaceae family, native to Madagascar. It grows 50 cm–1.2 m (20 in–3.9 ft) tall and 60 cm–1.2 m (24 in–3.9 ft) wide, wants full sun and low water, and is hardy to about 2 °C (36 °F). Space plants about 70 cm (28 in) apart.
Plan Crown of thorns in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Crown of thorns at a glance
| Type | Perennial shrub, evergreen |
|---|---|
| Family | Euphorbiaceae |
| Mature height | 50 cm–1.2 m (20 in–3.9 ft) |
| Mature spread | 60 cm–1.2 m (24 in–3.9 ft) |
| Spacing | 70 cm (28 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance none |
| Soil pH | 6–7.5 |
| Cold hardiness | About 2 °C (36 °F) once established (roughly USDA zone 10) |
| Heat stress | Likely above about 38 °C (100 °F) |
| Flowering | about 26–52 weeks after planting, for 26–52 weeks |
| Wind tolerance | Low |
| Pollinator value | Low |
| Edible | Not grown as food |
| Native to | Madagascar |
| Common in gardens of | 🇹🇭 Thailand, 🇸🇬 Singapore, 🇧🇷 Brazil |
Is Crown of thorns toxic?
- People: moderately toxic
- Cats: moderately toxic
- Dogs: moderately toxic
- Parts: sap (latex), stems
The milky latex is an irritant that burns skin, eyes and mouth, and swallowing causes vomiting and diarrhoea.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Crown of thorns
No well-documented helpful pairing. Group it with plants that like full sun and low water.
See Crown of thorns in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- Nong Nooch Tropical Botanical Garden (8 plants)
- Jardim Botânico do Rio de Janeiro (6 plants)
- Na ʻĀina Kai Botanical Gardens (4 plants)
Questions about Crown of thorns
- How far apart should I plant Crown of thorns?
- About 70 cm (28 in) apart, centre to centre. A mature plant spreads 60 cm–1.2 m (24 in–3.9 ft).
- Does Crown of thorns need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Crown of thorns need?
- Low water. Drought tolerance is high and waterlogging tolerance none.
- How cold-hardy is Crown of thorns?
- It tolerates about 2 °C (36 °F) once established, roughly USDA zone 10.
- When does Crown of thorns flower?
- About 26–52 weeks after planting, for 26–52 weeks.
- Is Crown of thorns poisonous to cats and dogs?
- For cats it is moderately toxic; for dogs moderately toxic; for people moderately toxic. The milky latex is an irritant that burns skin, eyes and mouth, and swallowing causes vomiting and diarrhoea.
- What grows well with Crown of thorns?
- There is no well-documented companion pairing for Crown of thorns. Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Flora & Fauna Web, National Parks Board, Singapore
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
Notes and assumptions
- Spiny stems and irritant latex: wear gloves when pruning and keep away from paths, children and pets.
- Rots in wet soil; the red, pink or yellow colour is in the bracts around tiny true flowers.
- Typical garden-form values; cultivars and local conditions differ.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Cassava Manihot esculenta
- Croton Codiaeum variegatum
- Poinsettia Euphorbia pulcherrima
- Pará rubber tree Hevea brasiliensis
- Mediterranean spurge Euphorbia characias
- Candlenut (kukui) Aleurites moluccanus
- Candelabra tree (naboom) Euphorbia ingens
- Griffith’s spurge Euphorbia griffithii