Sow outdoors, April-July, in a seed bed, 0.5cm (¼”) deep, directly into finely-prepared soil, which has already been watered. Seedlings usually appear in 21-35 days. Thin seedlings to 5cm (2″) apart, when large enough to handle. Keep moist. Plant out to flowering position in autumn, spacing 25cm (10″) apart. Or sow indoors, April-July, 0.5cm (¼”) deep, in a tray of compost. Water well and place in a cold frame, unheated greenhouse, or on a cool windowsill. Keep moist. Transplant individually, when large enough to handle, to 7.5cm (3″) pots. Gradually accustom young plants to outside conditions, before planting out into moist soil, September-October, 25cm (10″) apart. Flowers: May to July, the following year.