How to Grow Coneflowers

Where coneflowers grow best

Purple coneflower, Echinacea purpurea, is native to the prairies and open woods of the central and eastern United States. Clemson rates it hardy in zones 3 to 9 and NC State in zones 3 to 8. It grows in full sun, meaning six or more hours, to part shade.

The ideal soil is moist but well drained, though coneflowers adapt to many soil types and become drought and heat tolerant once established. What they do not handle is soggy ground. Sources differ on the coast: Clemson says coneflowers grow well across South Carolina except the coast because of poor salt tolerance, while NC State lists purple coneflower as salt resistant. On a beachfront site, try a few plants before committing a whole bed.

Plants grow 2 to 4 feet tall with strong stems that rarely need staking. The flowers draw butterflies and bees in summer, and NC State calls the plant deer resistant.

Planting potted coneflowers and divisions

Most gardeners start with potted plants. Set them at the same depth they grew in the pot, water well and keep the soil moist until they root in. Spring and early fall both work. For fall, Illinois Extension advises getting perennials in about six weeks before the first frost so roots can establish before winter.

USDA NRCS field spacing is 1 to 2 feet between plants and 2 to 3 feet between rows, and Clemson stresses that good spacing keeps air moving and leaves dry, which cuts disease.

Growing coneflowers from seed

Coneflower is easy to start from seed, and it self-sows readily in the garden.

Indoors. Sow in flats at an air temperature of 65 to 70°F and cover the seed lightly. Keep the surface misted. Seedlings appear in 10 to 20 days and are ready to move into pots 20 to 28 days after sowing.

Outdoors. Sow ⅛ to ¼ inch deep in a firm, weed-free seedbed. Clemson allows outdoor sowing in spring or summer up to about two months before frost.

Cold treatment. Seed sown in spring will sprout without chilling, but USDA NRCS notes that most sources find cold stratification improves germination. Keep seed moist in the refrigerator for about two months before sowing, or simply sow outdoors in late fall and let winter do the work.

Be patient. Plants from seed can take two or more years to reach good size. Some newer cultivars, such as ‘Glowing Dream’, are bred to bloom their first year.

Feeding, watering and dividing

Coneflowers are light feeders. Without a soil test, Clemson applies a slow-release fertilizer such as 12-6-6 at 1 pound per 100 square feet in late March or early April, just before new leaves emerge. Rich soil and extra fertilizer are not needed.

Water new plantings through their first season. After that, they need water only in long dry spells, and it is best applied at the base rather than overhead.

Divide every 3 to 4 years, in spring or fall, to keep clumps from crowding.

Seed heads, stems and wildlife

Coneflowers bloom from early summer and continue, with less vigor, into fall. Snip spent flowers if you want a tidy look, but leave the late ones. Goldfinches and other songbirds eat the seed through fall and winter.

Wait on fall cleanup too. Native bees nest in the hollow dead stems, so NC State suggests cutting stems back to 12 to 24 inches and leaving them standing until they break down. If you want to save seed, USDA NRCS harvests ripe heads in autumn before fall rains set in; slightly green heads can be dried in the sun first.

Common problems

• Aster yellows: stunting and deformed, green, tufted flower heads, spread by leafhoppers. Remove and destroy infected plants.
• Eriophyid mites: microscopic mites inside the buds cause tufts of distorted flower parts. Cut affected plants to the ground in fall and destroy the debris.
• Japanese beetles: an occasional pest in summer.
• Aphids: insecticidal soap, applied three times at 5- to 7-day intervals.
• Leaf spot and powdery mildew: reduce with good spacing and well-drained soil.
• Rabbits: can eat plants to the ground. Clemson suggests hot pepper wax sprays.

Cultivars and companions

Breeders have added red, orange, yellow, white and double forms to the original purple. Clemson’s South Carolina fact sheet describes cultivars such as ‘Magnus’, ‘White Swan’, ‘Ruby Star’ and ‘Kim’s Knee High’, and notes that ‘Magnus’ and ‘White Swan’ come reliably true from seed. It cautions that some newer hybrid series, such as Big Sky, may not be reliably hardy in poorly drained soil.

In Florida, UF/IFAS warns that some coneflowers last only a year or two before fading. Enriched, well-drained soil helps.

For a pollinator or native planting, NC State suggests butterfly weed and bee balm as plants that fill a similar role. Grouping them is a design choice, not a proven companion-planting effect.