The easiest echinacea to grow — germinates without stratification. Vigorous plants with large, purple-petaled flowers. Fibrous roots are easy to harvest (other species have taproots). Attracts and is a food source for bees. Also known as purple coneflower and eastern purple coneflower. Normally grown for 3–4 years for harvest of sizeable roots. Perennial in Zones 3–10. Ht. 24–36".