The name Crown of Thorns is derived from the belief by some that the crown of thorns worn by Jesus Christ at his crucifixion was made from stems of this plant.
Caution: Besides the sharp black thorns on its main branches and stems, the sticky, latex sap from broken leaves and stems can be a skin and eye irritant. If ingested, all parts of the plant are toxic to people and pets.
- Leaves – The thick, bright green leaves grow along the new stem growth.
- Flowers – The true flowers are small and green, surrounded by showy bracts in red, orange, pink, yellow or white.
Crown of Thorns, Christ Plant, Christ Thorn, Corona de Cristo
Crown of thorns is only perennial in USDA Hardiness Zones 9 – 11. In colder climates, it is often grown as a houseplant.
As with most flowering plants, the better the sun exposure, the more blooms you will get. However, crown of thorns will reliably bloom as long as it gets at least 3 – 4 hours of bright, direct sunlight per day. Outdoors, aim for a spot full sun. Indoors, place your plant in a west or south-facing winter during winter.
Crown of thorns will repeat bloom throughout the year. The actual flowers are the insignificant green centers, but they are surrounded by showy bracts that look like colorful petals.
Mature Plant Size
Outdoors, crown of thorns will grow into a shrub reaching 3 – 6 ft. tall. As a houseplant, expect it to reach only about 2 ft. in height.