Echinacea species, known as coneflowers, have daisylike flowers with prickly cone-shaped centers. In the summer, the flowers bloom at the ends of stalks in a variety of colors, including purple, white, yellow and pink. These perennials have oval dark-green leaves and grow in clumps that measure 1 to 5 feet tall and 1 to 2 feet wide. Depending on the variety, coneflowers grow in U.S. Department of Agriculture plant hardiness zones 2 through 9. They prefer moist, well-drained soil and full sun to partial shade, and will tolerate drought.
Native to the central and southeastern United States, purple coneflower (Echinacea purpurea) has 3-inch-wide violet, white or pink flowers with drooping petals. This species grows up to 3-1/2 to 5 feet tall and 1 to 2 feet wide. Cultivars, such as rose-pink “Magnus” and crimson-pink “Ruby Star,” usually have horizontal instead of drooping petals. These two cultivars and the purple coneflower species thrive in USDA zones 3 through 9.
Narrow-Leaf Purple Coneflower
At 1 to 2 feet tall, narrow-leaf purple coneflower (Echinacea angustifolia) is slightly smaller than purple coneflower. Also called Black Sampson, this species grows in dry prairies and poor soil in USDA zones 2 through 8. The light pink or purplish flowers have narrow petals that surround the center cone. This coneflower species prefers dry conditions and will not tolerate wet or poorly drained soil.
Hybrid coneflowers bloom in a variety of colors. For example, Echinacea “Tiki Torch” has horizontal orange petals that surround a reddish brown disk. It grows up to 29 to 31 inches high and 18 to 23 inches wide, and has a branched, bushy growth habit. “Cleopatra” has fragrant, semi-double or double yellow flowers with drooping petals and orange center cones. At 16 to 18 inches high and 12 to 16 inches wide, this cultivar grows well in a sunny border. Both cultivars tolerate drought and grow in USDA zones 4 through 9.
Other coneflower species include pale coneflower (Echinacea pallida) and yellow coneflower (Echinacea paradoxa). Both species have flowers with drooping petals. At up to 3 feet high and 18 inches wide, pale coneflower has 3-inch-wide, pink to purple flowers and lives only two or three years. It grows in USDA plant hardiness zones 4 through 8. Hardy in USDA zones 5 through 8, yellow coneflower grows up to 3 feet high and 1-1/2 feet wide. Its showy yellow flowers measure 3 to 6 inches across. Another variety, smooth coneflower (Echinacea laevigata), grows in USDA zones 3 through 8. It grows up to 5 feet high and 2 feet wide and has pink or purple flowers with narrow, delicate petals.
Unless a soil test indicates otherwise, coneflower varieties generally benefit from 12-6-6 fertilizer in early spring, before new leaves appear. Spread granular fertilizer around each coneflower plant at 3 tablespoons per 10 square feet. Avoid crowding coneflowers to prevent powdery mildew, which causes white growth on the leaves and flowers. To control aster yellows, which causes stunted growth and green petals, remove and destroy infected plant debris. Sucking insects such as aphids and eriophyid mites cause distorted leaves and flowers. Spray the entire plant surface with a dilution of 2-1/2 to 5 tablespoons of insecticidal soap per gallon of water every four to seven days to control these pests.
- Clemson University Cooperative Extension Service: Echinacea
- Perennials.com: Echinacea Purpurea “Ruby Star”
- Cornell University Cooperative Extension: Coneflower, Purple
- Perennials.com: Echinacea Purpurea “Magnus”
- Ladybird Johnson Wildflower Center: Echinacea Angustifolia
- Perennials.com: Echinacea “Tiki Torch”
- Perennials.com: Echinacea “Cleopatra”
- Missouri Botanical Garden: Echinacea Pallida
- Missouri Botanical Garden: Echinacea Paradoxa
- Clemson University College of Agriculture, Forestry and Life Sciences: Echinacea Laevigata -- Smooth Purple Coneflower
- Photo Credit Andy Sotiriou/Photodisc/Getty Images