Symphytum officinale
Family: Boraginaceae

Comfrey has long been well regarded by herbalists as a medicinal herb. Since the Middle Ages, when it was called knitbone and bone-set, comfrey has been used to aid the repair of fractures and broken bones and as a poultice for swellings, bruises and sprains. Its root has been shown to contain choline and allantoin which appear to assist the healthy proliferation of red blood cells and generally improve circulation. Today it is used externally only as most internal use has proved to be dangerous to health. Originating from the Caucasus, Symphytum officinale is a perennial, to 1 m (3 ft), with coarse, hairy leaves and strong stalks. Pretty, bell-shaped flowers in pendulous clusters bloom in late spring through summer in a range of colours, from cream to pink, purple, lavender and blue. Comfrey is useful to gardeners as it breaks down rapidly and helps accelerate decomposition of other plant material.

Cultivation

This hardy plant prefers a damp, shady place. Grow from seed or propagate by root division in autumn. Allow plenty of room for root growth. Comfrey tends to spread through the garden so establish a soil barrier if this proves to be a problem.

Climate

Zone 5 and above.