These herbaceous perennials thrive in full sun and well-drained soil, though they will tolerate light shade.
They prefer fertile, moisture-retentive soil but dislike waterlogging, so improve drainage if necessary. When planting, space them well apart to allow good air circulation, reducing the risk of fungal diseases.
Protect young plants from slugs and snails, especially in spring when new growth emerges.
Regular deadheading encourages prolonged flowering, and cutting stems back after the first flush may promote a second bloom. In autumn, cut plants down to the ground to keep them tidy and encourage fresh growth the following season.
Mature clumps can become congested over time, so divide them every few years in early spring or autumn to maintain vigour.
Mulching in spring with compost or well-rotted manure will help retain moisture and improve soil fertility.