Euphorbia milii (Crown of Thorns)
Botanical Information
| Family | Euphorbiaceae |
| Genus | Euphorbia |
| Species | milii |
| Category | Tropicals |
| Type | Shrub (evergreen) |
| Origin | Madagascar. |
Details
| USDA Hardiness Zone | 12a -12b |
| USDA Hardiness Ref. | |
| Canadian Hardiness Zone | Requires cool season protection under glass. |
| Canada Hardiness Ref. | |
| RHS Hardiness Zone | H1b |
| RHS Hardiness Ref. | |
| Temperature (°C) | 10 - 15 |
| Temperature (°F) | 50 - 60 |
| Height | 0.3 m - 2 m |
| Spread | 46 cm - 90 cm |
| Growth | Medium |
| Flowering Period | June, July, August |
Description and Growing Information
| General Description | A woody, succulent shrub with long stems covered in characteristic thorns, fleshy leaves and small flowers made up of two opposite petal-like bracts. |
| ID Characteristic | Wear gloves while handling: thorns are sharp and the latex sap is poisonous. |
| Shape | Low mounding to upright. |
| Landscape | Borders, rock gardens, specimen or container plant. Useful as a low hedge or edging. Grows well indoors. |
| Propagation | Stem cuttings. |
| Cultivation | Grow in full sun with dry to medium moisture in well-draining soils. Plants are tolerant of poor soil including dry, rocky and sandy mediums. They have low tolerance to temperatures below 2° C. Wet soils can be fatal, especially in winter. |
| Pests | Thrips, scale, mites and mealybugs. Leaf spot, botrytis blight, root and stem rot. |
| Notable Specimens | Niagara Parks Botanical Gardens, Niagara Falls, Ontario, Canada. Centennial Conservatory, Thunder Bay, Ontario, Canada. |
| Habitat | Moist sunny shrublands. |
| Bark/Stem Description | Smooth, glabrous stems covered in thorns. |
| Flower/Leaf Bud Description | Ovate insignificant flower buds at the apex of solitary flowering stems. |
| Leaf Description | Obovate with web-shaped base, fleshy, growing up to 6 cm long. |
| Flower Description | True flowers are inconspicuous and lack both sepals and petals. Each is surrounded by a pair of showy bracts which look like petals. |
| Colour Description | True flowers are greenish-grey. Bracts come in white, yellow or coral pinkish-red. Deep green leaves, medium green flowering stems. |
| Texture Description | Smooth, waxy. |
Photographs
Euphorbia milii, Form
Euphorbia milii, White Flowers
Euphorbia milii, Red Flowers
Euphorbia milii, Form (2)
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