Scientific Name
Euphorbia milii 'Primrose Yellow'
Common Name(s)
Christ Plant, Christ Thorns, Crown of Thorns, Siamese Lucky Plant
Scientific Classification
Family: Euphorbiaceae
Subfamily: Euphorbioideae
Tribe: Euphorbieae
Subtribe: Euphorbiinae
Genus: Euphorbia
Origin
Euphorbia milii 'Primrose Yellow' is a yellow-flowered cultivar of Euphorbia milii.
Description
Euphorbia milii 'Primrose Yellow' is a succulent shrub with branched, grayish-brown, 5- to 7-sided stems with many sharp spines and green, obovate leaves found mainly on new growth. It grows up to 6 feet (1.8 m) tall. Spines are grey and up to 1 inch (2.5 cm) long.
Flowers are yellow and subtended by a pair of conspicuous petal-like bracts.
Hardiness
USDA hardiness zones 10a to 11b: from 30 °F (−1.1 °C) to 50 °F (+10 °C).
How to Grow and Care
Crown of Thorns does well in even the poorest soil, provided it is well-drained and does not remain moist. It prefers a location in full sun but will tolerate some shade for a portion of the day. A tough plant, Crown of Thorns, is a good choice for a seaside location with salt spray or soil with high salt content. If you grow your Crown of Thorns as a houseplant, place it in an uncovered window, ensuring it receives maximum sunlight. Although drought tolerant, you can induce your plant to retain its leaves and bloom frequently by watering it regularly and giving it an occasional fertilizer. Check fertilizer labels and choose a basic, balanced formula without added micro-nutrients since the plant is sensitive to boron.
This plant benefits from some light pruning as it matures. Remove some older, leafless branches at the end of each growing season to stimulate new growth in spring. Clear away dead leaves and any dropped, matted flowers to allow the soil to dry well and reduce the likelihood of fungal disease. If you notice any brown stems or leaves on your plant, cut these back to healthy tissue to prevent rot from spreading through your plant. If you grow your plant indoors and wish to move it outside in warmer weather, keep it in partial shade for a week or two until it acclimates to bright sunlight.
Learn more at How to Grow and Care for Euphorbia.
Links
- Back to genus Euphorbia
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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