Water regularly, keeping the soil consistently moist but not waterlogged, especially during dry periods. Allow the top inch of soil to dry out slightly between waterings.

Reduce watering in winter when the plant is dormant. Ensure good drainage to prevent root rot.

Deadhead spent flowers regularly to encourage continuous blooming and prevent self-seeding if undesired. Lightly prune after flowering to maintain a tidy shape and promote bushier growth.

Remove any dead or damaged stems at any time.

Easily propagated from seeds sown directly outdoors in spring or autumn, or started indoors a few weeks before the last frost. Cuttings can also be taken in late spring or early summer and rooted in moist, well-draining soil.

Sweet William Catchfly is generally a short-lived perennial or biennial and may not require frequent repotting. If grown in pots, repot every 1-2 years in spring into a slightly larger container with fresh, well-draining potting mix.