May. If cut back after the first bloom more flowers may be produced later. Two blossoms are produced on each stalk. The plant grows in sun or light shade. Propagation is by division in spring or fall or by stem cuttings. The foliage turns reddish in the fall when frosted.
Cultivars have flowers of a different color.
The plant grows 1 to 2 feet tall and spreads 2 feet. In rich soil the plant may spread rapidly. Visuals associated with this text. This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.