Do You Deadhead Coneflowers?
The process of deadheading -- or removing the wilted blooms from a flowering plant -- focuses the plant's energy into healthy root and leaf growth instead of seed production. In some plants, it also encourages the plants to bloom again. The various coneflower species respond well to deadheading, but there are also good reasons for not deadheading coneflowers.
Coneflowers all belong to the plant family, Asteraceae, and the blooms are similar enough they can all be deadheaded the same way, or left on the plant for the same reasons. Not every type of coneflower blooms at the same time, so be on the lookout throughout the summer and fall to deadhead in a timely manner.
The common name "coneflower" applies to several genera, including Echinacea, Rudbeckia and Ratibida. All have a cone-shaped flower center, though plants in the Echinacea genus are the ones most often referred to as "coneflowers."
- Purple coneflower (Echinacea purpurea), which grows in U.S. Department of Agriculture plant hardiness zones 3 through 8, has purple-pink petals around an orange center. It grows 2 to 5 feet tall, and blooms all summer
- Yellow coneflower (Echinacea paradoxa), which grows in USDA zones 5 through 8, grows 2 to 3 feet tall. It blooms all summer, and has thin yellow petals around a brown center.
- Black-eyed Susan (Rudbeckia fulgida), which grows in USDA zones 3 through 9, is a sturdy perennial that grows 2 to 3 feet tall and blooms midsummer through fall. The daisylike yellow flowers have a black center.
- Gray-head coneflower (Ratibida pinnata), which grows in USDA zones 3 through 8, grows 3 to 5 feet tall and blooms in the summer. It has thin yellow flower petals that fold back from a 1-inch gray center.
- Mexican hat plant (Ratibida columnifera), which grows in USDA zones 4 through 9, is also called long-headed coneflower because the flower center can reach 2 inches high. It grows 1 to 3 feet tall, has yellow flower petals and blooms in the summer and early fall.
- Missouri coneflower (Rudbeckia missouriensis), which grows in USDA zones 5 through 8, grows 2 to 3 feet tall and blooms summer through fall. It has orange-yellow flowers with a black center.
Reasons to Deadhead
Deadheading coneflowers can encourage rebloom. Purple coneflower and yellow coneflower will rebloom without deadheading, but black-eyed Susan must be deadheaded if you want reliable repeat blooming all summer and into fall.
Removing spent blooms also prevents self-seeding. If you don't want the plants to spread throughout the garden, make sure you deadhead plants before the seed heads ripen. Removing the flowers as soon as they are finished blooming also keeps the garden looking neat and tidy.
Coneflowers have thick stems, so use sharp shears or pruners to remove the blooms. Once a flower is dead, remove it by making a clean cut just above the first group of leaves below the flower. Before using pruning tools, disinfect them by soaking for five minutes in a solution of 1 part household bleach or pine oil cleaner mixed with 3 parts water. Rinse with clean water before use.
Leaving the Seeds
If you decide not to deadhead coneflowers, the seeds will attract birds to the garden. The seeds that birds don't eat fall to the ground and easily sprout to create more plants. Self-seeding can result in a large number of seedlings in the spring, which will start blooming after about two years.
The flower center of the coneflower is where seeds develop. After the petals fall off, these seed heads often remain upright in the garden throughout all or part of the winter. This provides winter interest in the garden in the form of dark-colored cone-shaped seed heads, and birds that are attracted to the seeds.