Ricinus: Castor oil plant
Height 1.5m (5ft)
Planting distance 90cm (3ft)
Tender shrub grown as half-hardy annual
This tropical plant, whose seeds are used to make castor oil, is a particularly striking half-hardy annual. Robust and shrubby, it will grow 1.5m (5ft) high, and nearly as wide, in the course of a year. The leaves, up to 30cm (1ft) across, are hand-shaped. In the species, Ricinus communis, these are green, but varieties exist with brown, maroon or bronze-green foliage.
Castor oil plants make eyecatching specimen plants.
Soak the seeds in water for 24 hours to speed up germination, then sow them in individual pots under glass in late winter to early spring. Keep at a temperature of 21°C (70°F). Harden off before planting out in late spring.
Space the plants 90cm (3ft) apart in rich soil and in a sunny site. Stake in exposed sites.
Pests and diseases