Lot Location: 6.3
Best grown in humus-rich, evenly moist, well-drained soils in full sun. Grows well in sandy soils. Intolerant of wet, heavy soils. Plants require sharp soil drainage, particularly in winter when root rot can be a severe problem. Best with full sun exposure, but tolerates some light shade in hot summer climates. To the extent possible, located in areas protected from the wind. Promptly remove spent flower spikes. Crowns benefit from winter protection in USDA Zones 5 and 6. Tie leaves together in late fall to form a canopy over the crown in order to prevent water from settling in the crown and freezing. Root mulch in winter is also advisable. Cut back foliage to 3” above the ground in early spring in anticipation of the new growing season. Established clumps are best left undisturbed. If division becomes needed because of overcrowding, consider severing offsets from the edge of the plant to minimize the amount of disturbance to the rhizomes. Species plants may be grown from seed. Named cultivars usually must be divided, however, because the flower color typically will not come true from seed or viable seed will not be produced.
‘Elvira’ is a patented hybrid cultivar that will not produce viable seed.