Sow seed on the surface of a good, freedraining, damp seed compost. Do not cover the seed. Place in a propagator or seal container inside a polythene bag at 20-25Â°C (68-77Â°F) until after germination which usually takes 10-21 days. Do not exclude light, as this helps germination
Transplant seedlings when large enough to handle into trays or 7.5cm (3in) pots. Gradually acclimatise plants to cooler conditions for a few weeks before planting out after all risk of frost, 23-30cm (9-12in) apart. Remove spent flowers regularly to encourage further blooming.