An easy-to-grow garden perennial with showy daisy-like flowers in midsummer, the purple coneflower (Echinacea purpurea) grows 3 to 5 feet tall and about 2 feet wide. Horticulturists today have bred or selected seedlings of plants that develop a broader range of flower colors or mature growing heights. Cultivars with white, yellow, red, pink, orange, green and lavender shades exist, allowing gardeners a good choice for a perennial border. Grow purple coneflower in USDA hardiness zones 3 through 9.
Purple coneflower naturally grows in the southeastern third of the United States. The natural range of this herbaceous perennial wildflower extends from Iowa and Illinois to Ohio and Virginia south to northern Florida and westward to extreme northeastern Texas.
Sunny prairies, rolling hillsides and open areas in woodlands are the basic habitats in which you find the purple coneflower growing. Soils must have good drainage, but can range from gravelly or sandy to deep fertile loams and seasonally dry banks of streams that may have clay soils. Although drought tolerant, excessive heat or intense sunlight on plants growing in too dry of a soil causes the plant to wilt and reduce its amount of stems and subsequent flowering, according to Illinois Wildflowers website.
Besides soil, the climate in the eastern United States defines the extent of the natural range of the purple coneflower. This perennial needs a winter dormancy with cool to cold temperatures in order to return year after year from its thick, black roots that are short rhizomes (fleshy underground horizontal stems). This plant survives where winter low temperatures drop between minus 25 degrees to plus 20 degrees Fahrenheit. It also grows where there are no more than 150 days of summertime temperatures above 86 F, as based on information from the American Horticultural Society's "A-Z Encyclopedia of Garden Plants."
Role in Ecosystem
A variety of nectar-loving insects rely on the purple coneflower to supply food in the summertime. Native bees and butterflies relish the nectar while pollinating the flowers, resulting in the copious production of seeds. Some species of butterflies and moths also lay eggs on the coneflower's leaves and supply nourishment to developing larvae, according to Illinois Wildflowers. As flower heads mature and dry by late summer and into the autumn, the seeds are eaten by many small songbirds such as the eastern goldfinch.
Both birds and the wind help scatter the seeds of purple coneflower around the landscape. If the soil is not shaded by nearby prairie grasses, other wildflowers or overly shaded from the sun by nearby woodland trees and shrubs, the seeds readily germinate and become new plants. In fact, according to the Lady Bird Johnson Wildflower Center, purple coneflower is considered an "aggressive" plant--meaning it will reseed and spread its numbers to the point of being a weed that must be managed.