Echinacea purpurea, or Purple Coneflower, is a very hardy perennial plant native from Ohio to Iowa and south to Louisiana and Texas. Plants reach 3-6 feet(1-2 m) in height with a spread of around 2 feet (60 cm). Leaves are broadly lanceolate, coarsely toothed, with long petioles. The plant's thick black edible roots are reputed to increase the body's resistance to infections. A tincture made from the root has been used as a remedy for corns. It is hardy in the landscape in USDA zone 4-8.
Blooming: Echinacea purpurea plants bloom from late spring into fall. The showy purple flowers reach up to 4 inches (10 cm) across. As with all Asteraceae, the apparent "flowers" are actually inflorescences, which in this plant include 12-20 showy ray flowers and numerous disc flowers on the dome. The heads are very showy and have a long vase life, so they make great cut flowers.
Culture: Echinacea purpurea need full sun to very light shade with a rich, well-drained soil mix. In the greenhouse, we use a soil mix consisting of 1 part peat moss to 2 parts loam to 2 parts sand or perlite. The plants are well watered and allowed to dry slightly before watering again. During the growing season, plants are fertilized on a monthly basis with a balanced fertilizer. During winter months, water is restricted and plants are placed into the cool rooms for winter dormancy. Temperatures are dropped to 48°F (9°C) and water is withheld until spring.
Propagation: Echinacea purpurea is propagated by division or from seed. Division should not be practiced too frequently. Root sections with bud should be placed just under the soil surface. Roots planted too deep will not come up. Seeds are sown 0.25 inches (6 mm) deep. Germination should take place in 14-21 days at 70-75°F (21-23°C).
Echinacea purpurea was featured as Plant of the Week June 23-29, 2006.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.