12-18 in. (30-45 cm)
Foliage height ranges from 6 to 18 inches; flower spikes can reach 24 inches tall.
24-36 in. (60-90 cm)
Select a site with full sun to light shade and well-drained soil. In areas with hot summers, light shade is preferred.
Plant in spring or fall, spacing plants 1 to 2 feet apart depending on the variety. Prepare the garden bed by using a garden fork or tiller to loosen soil to a depth of 12 to 15 inches, then mix in a 2- to 4-inch layer of compost. Dig a hole twice the diameter of the plant's container. Carefully remove the plant from its pot and place it in the hole so the top of the root ball is level with the soil surface. Carefully fill in around the root ball and firm the soil gently. Water thoroughly.
Remove dead foliage in early spring, then apply a thin layer of compost, followed by a 2-inch layer of mulch to retain moisture and control weeds. Water plants during the summer if rainfall is less than 1 inch per week. Cut back flower stalks after blooms fade. Divide plants in early spring every 3 or 4 years or when the stems become woody or the plant falls open at the center. Lift plants, divide the root ball into clumps, and replant.