Sow February to June onto the surface of a good, free-draining, damp, seed compost. Cover with a very fine sprinkling of compost or vermiculite. Place sown container in a propagator or seal container inside a polythene bag at a temperature of 15-20C (59-68F) until after germination which usually takes 10-14 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 young plants to cooler conditions for a few weeks before planting out after all risk of frost, 30-45cm (12-18in) apart.