Water tansy regularly, especially during dry spells, but ensure the soil drains well to prevent waterlogging. Allow the top inch of soil to dry out between waterings.

Established plants are quite drought-tolerant once settled, reducing watering needs significantly.

Deadhead spent flowers to encourage more blooms and prevent self-seeding. Cut back the plant by about one-third to one-half in mid-summer after the first flush of flowers to promote a bushier habit and a second bloom.

In late fall or early spring, cut the entire plant back to the ground.

Tansy is easily propagated by division of clumps in early spring or fall. Stem cuttings can also be taken in late spring or early summer. Sow seeds indoors in early spring or directly outdoors after the last frost.

Division is the most common and reliable method.

Tansy is a perennial that does not typically require frequent repotting if grown in the ground. If grown in containers, repot every 2-3 years in spring into a slightly larger pot with fresh, well-draining potting mix.

This helps to refresh the soil and prevent root-bound conditions.