Coreopsis
Perennial

USDA Zones: 3 - 9
Light: sun
Height:  15 to 36 inches
Width:  12 to 24 inches
Flower Colors: shades of yellows, cream, pink, and blue
Bloom Time: summer - fall
Special Features:
Attracts Butterflies
Beds/Borders
Cutting
Drought Tolerant
Easy to Grow
Flowers
Rock Garden
Self-Sowing
Showy Flowers
Tolerates City Conditions
Tolerates Dry Soil
Tolerates Infertile Soil
Tolerates Salt
U.S. Native
US Native/Wildflower
Companion Plants:
Perennial blue salvia 'May Night'

An American native, coreopsis is easy to grow, with sunny flowers held atop long slender stems. It's not very picky about soil, tolerating poor, shallow, chalky or dry soils. It blooms usually in yellows and golds, but creams and a pink type (Coreopsis rosea) are available. Coreopsis grandiflora is the most commonly grown, with daisylike 2-inch flowers. However, thread-leaf coreopsis (Coreopsis verticillata), with its feathery foliage and smaller flowers, has recently also become very popular. Long-blooming -- it will flower from early summer through frost -- it's a must-have for the perennial border.

Notable Varieties
Coreopsis grandiflora 'Early Sunrise' and 'Sunray' are heavy bloomers growing 18 to 24 inches.
Coreopsis verticillata 'Zagreb' and 'Moonbeam' grow 15 to 18 inches tall and are also heavy bloomers.

Care
Plant coreopsis in full sun in any well-drained soil. Coreopsis grandiflora has a life span of 2 to 3 years if not divided, but may reseed itself. Deadheading fading flowers is critical for a long bloom time. (It's easiest just to shear them all after the first flush of bloom.)

Planting
Plant established plants in spring or fall. Space 12 to 18 inches apart. Divide every two to three years in spring.

Pests and Diseases
Mildew is often a problem for coreopsis; avoid wetting leaves but keep soil moist. Leafspot, aphid, and cucumber beetles can be combated by applying insecticidal soap spray.