A poultice of Comfrey heals wounds, burns, sores, and bruises. It is a powerful remedy for coughs and ulcers. Comfrey is most often used for healing broken bones and sprains. It also is used in treating asthma. Large amounts taken over a period of time can cause liver damage, but there are no indications of problems with using it externally. Used internally, it is best and safest to use a tea, rather than capsules.
Comfrey prefers well-drained soils and partial shade. It grows from Canada to Georgia, and as far west as Missouri, in the wild. It is a perennial that grows to 3 feet high. It can be started from seed, but you will be more successful with cuttings. Once established, it will spread vigorously. Harvest the leaves when the flowers are in bud, and the roots in the autumn, after the first frost.