Sow early spring to early summer outdoors where they are to flower. Prepare the ground well and rake to a fine tilth before sowing. Sow 3mm (1/8in) deep in rows 30cm (12in) apart. Germination usually takes approximately 21 days. When large enough to handle thin out to 23cm (9in) apart. They prefer a sunny open site but will grow in most sites and soils. An early autumn sowing can be made in sheltered areas for earlier flowers the following year.