Long a fixture in old Southern gardens, this bold, striking plant from Africa and Asia remains a source of dread for children with digestive problems: Mothers still prescribe a spoonful of foul-tasting castor oil, pressed from the plant's seeds, to clean you out. Enemies of the former Soviet Union had even more to fear. Ricin, a poison extracted from the seeds, was used by the KGB to dispatch selected targets (it is deadlier than cyanide). Fortunately, castor oil doesn't contain ricinbut ingesting just one of the beautifully marbled beans can cause serious illness, so do not plant this shrub where small children play.
Soak seeds in water overnight before planting in warm soil. Castor bean can provide a tall screen or accent in a hurry; it grows 615 ft. tall and half as wide in a single season. The plant overwinters in the Coastal and Tropical South and can become woody and treelike there. Large, coarsely lobed leaves are 13 ft. across on young, vigorous plants, smaller on older plants. Small white flowers are borne on foot-high stalks in summer; they're unimpressive but are followed by attractive, prickly seedpods. Selections include 'Carmencita', with deep purple leaves and leafstalks and coral-red seedpods; 'Dwarf Red Spire', a lower grower (to 6 ft.) with red leaves and seedpods; 'Sanguineus', with blood-red leaves and stems; and 'Zanzibarensis', sporting huge green leaves with white veins.