Modern cultivars average about 3 feet in height and grow equally well in dry sunny areas or moist shady places. The blooming occurs in July and August. The best growth is from plants disturbed as little as possible. Division is done in fall or early spring. Once the divisions are made, replant immediately.
Older plants divide most easily.
A few plants can be obtained from rooted pieces detached from the outer edge of the clump. Stem cuttings may also be used. The seed germinates in 25 to 30 days at 70 degrees. A cold moist treatment may be necessary if seeds are planted indoors. Visuals associated with this text.