All comfrey cuttings are clones of Bocking 14, which will not produce seed. The lilac colored flowers produce an abundance of nectar and pollen for a wide variety of bees. All green parts of the plant are high in a wide variety minerals and other nutrients, enriching the upper layers of the soil profile as fresh minerals are brought up from lower soil horizons. Wonderful as a border, in-situ mulch producer, and a soil builder. Once established, they are essentially permanent. Even with 95% root removal, they would probably re-sprout and grow back.