Echinacea purpurea 'White Swan', or White Coneflower, is a very hardy perennial cultivar of the old standard Purple Coneflower. The plant will reach 2-3 feet (0.6-0.9 m) in height, with a spread of around 2 feet (60 cm). Leaves are broadly lanceolate, coarsely toothed with long petioles. This is the third year for this cultivar to grow in our yard. The first 2 years, they bloomed sporadically and were not that showy. This year, however, I am very impressed with the plant and its bloom. Here in Oklahoma, they tend to be slow starters, but the wait is well worth it. They are very showy when interspersed with purple coneflowers. Plants are hardy in USDA zones 4-8.
Blooming: Plants will bloom from late spring into fall. The white heads will reach up 4 inches (10 cm) across. The ray flowers have 12-20 drooping petals and the domed disc flowers are covered with spiny golden yellow flowers. They are very showy. The flowers have a good vase life and therefore make a great cut flower.
Culture: Echinacea purpurea 'White Swan' 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, the plants are fertilized on a monthly basis with a balanced fertilizer. In the landscape, plants are very drought tolerant and only need moderate water requirements. In our yard, we fertilize in the early spring before new growth starts and again in mid spring just before blooming starts. In the greenhouse during the winter months, water is restricted and the plants are placed into the cool room for winter dormancy. Temperatures are dropped to 48°F (9°C) and water is with held until spring.
Propagation: Echinacea purpurea 'White Swan' is propagated by division or from seed. Division should not be practiced too frequently. Root sections with buds should be placed just under the soil surface. Roots planted too deep will not come up. Seed 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 'White Swan' was featured as Plant of the Week July 11-17, 2008.
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Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically 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.