Short-lived perennial that is winter hardy to USDA Zones 3-10. Easily grown in average, medium, well-drained soils in full sun. Prefers moist, organically rich soils that drain well but tolerates some dry soils. Performs poorly in unamended heavy clay soils. Many hybrid cultivars may be grown from seed. For those that can, sow seed directly in the garden after last frost date or start seed indoors 4-6 weeks earlier. Set seedlings out after last frost date. Space plants 12-18†apart depending on size. Deadheading spent flowers is not necessary but will tidy the planting and may encourage additional bloom. If flowering declines in summer, consider cutting back plants to encourage a fall bloom.
