Plant in a sheltered, sunny location with moist, fertile soil. While they can tolerate some dryness, consistent moisture will encourage lush growth and abundant blooms.
If growing them in large containers, protect the roots from harsh winter conditions by wrapping pots and plants using horticultural fleece or move to a sheltered spot such as a southerly facing wall.
Mulch the base of border plants with a dry material like bark chips to insulate the roots and prevent frost damage. Regularly remove spent blooms to prolong flowering.
Pruning should be done in late winter or early spring, before new growth emerges. Prune back to strong, healthy buds to encourage new growth and shape the plant. Removing old and damaged wood will also help to improve air circulation and reduce the risk of disease.