Grow in average, medium moisture, well-drained soils in full sun. Prefers rich, humusy soils. Intolerant of wet, heavy soils. Locate in areas protected from wind. Promptly remove spent flower spikes. Crowns benefit from winter protection in USDA Zones 5 and 6 (mulch or tie leaves together forming a canopy over the crown so as to prevent water from settling on the crown and freezing). Established clumps are best left undisturbed.