Crown of Thorns
Also known as
Christ Plant, Christ Thorn, Corona de Cristo, Corona de Espinas
Keep this plant’s care guide close at hand.
Get the appAbout Crown of Thorns
Euphorbia milii, commonly called Crown of Thorns, is a shrubby, succulent euphorbia native to Madagascar’s dry spiny forests. It forms woody, gray-brown stems armed with paired, sharp thorns. Fleshy, obovate leaves cluster near the stem tips and are shed from older stems in drought or low light. The showy “flowers” are actually colorful bracts surrounding tiny cup-shaped cyathia; bract colors range from red and pink to salmon, yellow, and white, and can appear nearly year-round in strong light. Its milky latex sap is characteristic of Euphorbia and can irritate skin and eyes. In containers, plants typically reach 1–3 ft (30–90 cm), while landscape specimens in frost-free climates can grow larger and more branched. It thrives in bright sun, lean, fast-draining soil, and modest water, making it an excellent low-maintenance houseplant or patio specimen. Pruning encourages a compact, floriferous habit, and careful handling is essential due to spines and sap. Durable and drought-tolerant, it rewards consistent light with prolific, long-lasting bloom cycles.
Taxonomy
Properties & Requirements
How to care for Crown of Thorns
Water
Water thoroughly, then allow the soil to dry well before the next drink. In warm, bright conditions, this may mean watering every 7–14 days; in winter or low light, extend intervals to 2–4 weeks. Aim to let at least the top 50–75% of the mix dry, or wait until leaves just begin to soften slightly. Always use a pot with drainage and empty saucers. Err on the dry side—consistent overwatering is the most common cause of decline.
Light
Provide very bright light to full sun for 4–6+ hours daily to maximize bract production. Indoors, a south or west window is ideal; supplemental grow lights (20,000–40,000 lux) maintain compact growth. Outdoors in warm climates, give full sun to light afternoon shade, acclimating over 1–2 weeks. Insufficient light leads to sparse blooming and stretched stems; too abrupt high-intensity sun after shade can scorch tender leaves.
Nutrients
Feed lightly during active growth (spring through early fall). Use a balanced, dilute cactus/succulent fertilizer or a bloom-leaning formula with lower nitrogen and slightly higher phosphorus/potassium at 1/4–1/2 strength every 4–6 weeks. Avoid heavy, frequent feeding that encourages lanky growth. Flush the pot with plain water every 2–3 months to prevent salt buildup. Do not fertilize in winter unless the plant is actively growing under high light and warmth.
Temperature
Best kept warm: 65–85°F (18–29°C) with good airflow. It tolerates higher heat if watered appropriately and shaded during extreme midday sun. Protect from cold; growth slows below 60°F (16°C) and damage occurs near or below 50°F (10°C). Avoid frost entirely. Indoors, keep away from cold drafts or air-conditioning blasts. A slightly cooler, drier winter rest (55–65°F/13–18°C) can help concentrate spring bloom.
