Euphorbia milii

Description

Crown of Thorns is a deciduous, herbaceous, perennial shrub with bright green leaves and greenish flowers. The flowers are enclosed within long-lasting and bright bracts of red or yellow. The plant is loose in form, spiny and irregularly shaped, with thick, black spines and its historic presence in the Middle East led to the belief by some that the stems of this plant had been used in Christ’s crown of thorns, hence the common name. In its country of origin (Madagascar) the plant will grow to 5 or 6 feet tall; however, in the United States, it typically grows to 3 feet, or 2 feet when grown as a houseplant.

Crown of Thorns grows best in dry to medium moisture, well-drained soils in full sun. Because it does not like wet, cold soils or temperatures below 35 degrees F. It is an easy to grow indoor plant where it prefers a sunny location in soil-based potting mix. If grown outside in hot summer climates, provide the plant with midday shade and moderate moisture for better flower bloom. You can propagate the plant from tip cuttings; however, because the resulting white latex sap causes a mild poisonous reaction when in contact with skin or eyes, wear gloves when working with this plant.

Sticky, showy, paired-bract flowers on gray stems with long spines identify this plant. Cyclical leaf drop is normal, but messy and preceeds the plant’s resting season (usually winter).  The flowers will bloom throughout the year. The long spines are dangerous to inattentive gardeners, children and pets. The plant is often used as a specimen plant for interiors with high light or as annual outdoor plant.

Crown of Thorns prefers bright light, dry soil and low relative humidity. You can propagate the plant from cuttings, but let sap dry before placing the cutting in a growing medium.

Flower Description:  Flower bloom time depends on the plant location. When grown in tropical or sub-tropical conditions, blooms occur throughout the year, but especially in Spring and Summer. In warm southern climates, blooms usually occur in winter and spring. When grown as a houseplant, it will bloom from late winter well into fall. Green flowers are subtended by red or yellow showy paired bracts in cymes on long peduncles up to 2 inches. Several miniscule unisexual cyathia, enclosed in a 5-lobed involucre, bear glands and are subtended by a showy pair of bracts. The bracts are ovate, red, salmon or yellow, and about 1/3 of an inch.