Coneflowers (echinacea), especially the purple coneflower, are popular for borders and wildflower gardens. Recent hybrids have introduced orange, pink, yellow, red and white versions, in a wide range of heights. Like the original species, the hybrids are easy to care for. All are hardy to zone 4 and many to zone 3.
Coneflowers require lots of sun, so plant them in an area that gets at least eight hours of full sun each day. Because they are prairie flowers, coneflowers don’t need particularly rich soil, and rarely need fertilization. If you feel the need to fertilize, an ordinary garden fertilizer will do. Coneflowers don’t thrive in heavy, wet soils, so plant them in a well-drained location, preferably in sandy soil.
Consider the characteristics of each hybrid before you plant them. Although the Purple Coneflower grows to 36 inches tall, the hybrids range in height from 11 to 60 inches. Dwarf varieties should be located towards the front of a flower border so they are not shaded by other plants, which will result in less healthy coneflowers.
Aster yellows, a disease which causes flower buds to distort, sometimes attacks coneflowers. Once infected, there isn’t a remedy–diseased plants should be promptly removed and disposed of to reduce further spread. Healthy plants are more resistant, so keep the flower bed weeded, space the plants to allow air circulation, and thin coneflower stands when they become too dense.
Aphids, leaf fleahoppers and aster leafhoppers attack coneflowers and can do considerable damage. Healthy plants resist pests naturally, so keep the flower bed weed-free so weeds don’t compete for water or harbor insects. Apply insecticidal soap to control pests if they do appear.