Symphytum officinale / Comfrey

Comfrey should be in the toolkit of anyone interested in composting. It is incredibly high in nutrients, including silica, nitrogen, calcium, iron, magnesium, and potassium. This also makes it a useful ingredient in compost tea. Also used in traditional herbal medicine and a companion plant with fruit trees. Use this species if the primary use will be medicinal. Use Russian Comfrey if you're more interested in composting.

This is an aggressive species that spreads by rhizomes so be sure to plant it somewhere you don’t mind it spreading. Deadhead to prevent self-sowing. Grows best in full sun to part shade and average soil, though very adaptable. Reaches 2 to 4 feet.