Sowing – Sow seeds on the surface of a good, free-draining, damp, seed compost and cover with a fine sprinkling of compost or vermiculite. Place container inside a polythene bag or propagator at 21-25C (70-75F). Germination takes 14-21 days. Do not exclude light, as this helps germination

Growing – Transplant seedlings when large enough to handle into trays of 7.5cm (3in) pots. Gradually acclimatise plants to cooler conditions for a few weeks before planting out after all risk of frost, 23cm (9in) apart. Overwinter late summer sowings in a cold frame and plant out the following spring.

Flowers – May to August