|Vigorous, rhizomatous, clumping perennial with rosettes of coarse, hairy, medium green leaves up to 10 inches long. Bears forked cymes of drooping, bright blue flowers throughout summer. Plant 2 to 3 feet apart in rich soil. Comfrey contains protein and an impressive list of vitamins, though it can cause stomach discomfort when ingested. Remove flower stalks to keep flower production high.