Hybrid coneflowers (Echinacea spp.) combine the qualities of many fine North American coneflower species. Improved hardiness, better flowering and disease resistances or a wider array of flower color choices result from the hybrid crosses. Full sun and moist, well-draining soils that are rich in organic matter ensure healthy plants. Divide plant clumps every few years to renew vigor.
Hybrid coneflowers are bred from North America native coneflower species such as purple coneflower (Echinacea purpurea), pink coneflower (Echinacea pallida) and Tennessee coneflower (Echinacea tennesseensis), among others. Overall, coneflowers are winter hardy in USDA hardiness zones 4 through 9. However, based on the lineage of the hybrid, small variations in the USDA zone range can occur. Consult plant labels or literature to determine specific limits to winter or other climatic elements, such as summer heat or humidity, in the overall hardiness of hybrids.
For best growth, plant hybrid coneflowers in a deep, well-draining soil that is rich in organic matter. Mulch and compost on the soil provide adequate nutrients for growth. Moist soils must not become soggy after typical rainfall events. Soils that are very dry, acidic or alkaline can cause slight stunting of growth. Soil pH should fall between 6.0 to 7.8.
Flowering will be most prolific on coneflowers receiving at least six to eight hours of direct sunlight daily, usually called a full sun exposure. Light, dappled shade is acceptable, but flowering may be reduced or stems may be longer and less resilient to wind.
Drought tolerant once established, coneflowers need a moist, well-draining soil in the growing season. Slightly drier soils are tolerated, but the number of stems and flowers may be slightly reduced depending on stress created by lack of moisture. Avoid soggy soils or areas that are known to flood after casual rainfall events.
As the blooms fade in summer, cut them away to encourage secondary branching and more new blossoms. Consider leaving flowers in very late summer to ripen into seedheads to provide needed food for songbirds in the winter. Cut down the frost-dried stems in mid to late winter to allow the new growth in the spring to emerge unimpeded.
Dig up and divide coneflower clumps every three to four years in the early spring before new growth femerges. Plants improve vigor after being divided and replanted.