Crown-of-Thorns (Euphorbia splendens) Unusual because of its curving stems, crown-of-thorns should be used as a living sculpture. Leaves drop occasionally, but the red flowers (bracts) that appear at the tips of spiny branches are attractive. Light Place in high light (south exposure). Water Allow soil surface to dry out between thorough waterings. Water less in fall when the plant is dormant. Use tepid water because cold water causes leaves and blossoms to drop. Temperature Maintain an evenly warm temperature. Avoid hot and cold drafts. Comments Plant in sandy soil rich in organic matter. Prune to desired shape. Feed during flowering, usually January through March. The pale leaves drop periodically, which is normal. Propagate by tip cuttings or sections of root one to two inches long taken after flowering.