Easily grown in a well-drained loam, preferring a position in full sun but tolerating shade. Prefers an alkaline soil but tolerates a slightly acid soil. Plants grown in rich soils produce more foliage at the expense of flowering. Hardy to about -25°c. Members of this genus are rarely if ever troubled by browsing deer.

None known

Seed - sow early spring or autumn in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Division in spring. Larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer.

Locally common in dry open woods, prairie hillsides, roadsides, old fields and waste places.