Water regularly during the growing season, allowing the soil to dry slightly between waterings. Reduce watering in autumn and winter. Ensure good drainage to prevent waterlogging, which can lead to root rot.

Overwatering is the most common cause of problems for this plant.

Deadhead spent flowers regularly to encourage further blooming and maintain a tidy appearance. Cut back the plant in late autumn or early spring to remove dead or withered stems and to shape the plant.

Pruning promotes vigorous new growth.

Propagate by division of clumps in spring. Sow seeds in autumn or early spring, either outdoors or in a cold frame. Seeds may require a period of cold stratification.

Division is the most common and reliable method for home gardeners.

Young plants may benefit from repotting annually into slightly larger containers. Mature plants are generally best left undisturbed and can be grown in the ground or in larger pots.

Repot in spring before new growth begins if necessary.