Need moisture in spring and for a month after bloom. No need for watering them during the summer. Best performance begins third year after planting. Leave undisturbed for years. They will form large clumps.
Blooms have delicate appearance.
Plant smaller varieties 3-4 inches apart and 4 inches deep. Colors white, yellow, purple, pink, greenish, and combinations. Generally hardy zones 4 through 9. Lots of different flower forms, from tight formal globes or spidery delicate types to loose informal clusters. Taller ones will probably need staking due to their height, but certainly make spectacular cut flowers.