Coneflowers, or Echinacea purpurea, are perennial flowering plants named for their mounded, cone-shaped flowers. Native to the United States, coneflower varieties typically grow throughout the central and eastern regions of the U.S. Favored for their garden versatility, coneflower cultivars offer blooms in shades of white, pink, purple or yellow. Established coneflowers spread through seeds and clumping.
Coneflowers open on tall stems surrounded by rag-leaf foliage. Part of the aster family, these flowers mature up to 4 ft. tall. They tolerate full sun, and thrive in cutting flower gardens with daisies, coreopsis, yarrow and other perennial flowers. Due to their deep tap root, coneflowers adapt to low water or xeriscape gardens. Scatter their seeds with wildflower blends for an easy-care border or fence garden. Coneflowers form a spreading clump that fits well into ornamental grasses in background plantings with shorter perennials, annuals or bedding plants in the foreground. As coneflowers mature and spread, they fill gaps where other flowers die back.
Coneflowers spread by seeding. Flowers open in summer and bloom through autumn. The center cone, looking like a small hedgehog, matures and dries with seeds in the cone pods. In autumn, the small dry seeds naturally spill out on the ground, are scattered by wind or fall out as the plant dies back. Birds such as finches eat the seeds and scatter them in bird droppings. The seeds grow quickly in loose soil but also will root in poor soil or cracks in clay soil. The seeds winter over and germinate in spring.
Coneflowers grow in clumps, growing outward from the central foliage mound and tap root. Coneflowers spread in clumps up to 2 ft. in diameter. This plant mass looks like one plant and must be divided every three to four years. If the clumping plants are not divided, the overcrowded roots do not reach the soil for enough nutrition and the plant declines. Divide the spreading coneflowers in spring or fall, digging up the clumps and cutting or hand-separating them into smaller clumps. Replant for new coneflowers, allowing room for the new plants to spread.
Sometimes coneflowers spread too easily. They scatter hundreds of seeds that take root in rich soil, invading other flower space. Deadhead the flowers and discard the heads to reduce self-sowing. Deadheading also encourages longer blooming seasons. The spreading, shaggy clumps look unkempt in some gardens. Add shorter flowers in front of the coneflowers or plant coneflowers among evergreens like rosemary and lavender plants. The perennial herbs blend with the coneflower clumps, minimizing their untidy look.