PERENNIAL. Comfrey is a perennial shrub that is native to Europe and temperate parts of Asia. Fond of moist soils, comfrey has a thick, hairy stem, and grows 2 - 5 feet tall. It is used topically (do not ingest) to treat wounds and reduce the inflammation associated with sprains and broken bones. The roots and leaves contain allantoin, a substance that helps new skin cells grow, along with other substances that reduce inflammation and keep skin healthy. Comfrey has light purple, pink, or white flowers that hang in clusters. Comfrey leaves make great compost. Harvest the leaves as needed to add to your compost pile.