They should be grown in fertile well-drained soil, they are frost-tender to fully frost-hardy plants. You can propagate the shrubs from cuttings in the summer, annuals from seed in autumn and perennials by division in spring.
You can propagate the shrubs and climbers by semi-ripe cuttings in the summer, and the annuals by seed in spring and the perennials by division in spring.
Pests, diseases or disorders
Aphids, grey mould, powdery mildew, leaf spots and red spider mites.