Sow seeds outdoors in free draining soil in mid spring when the soil has warmed up. Sow 2-3 seeds in stations 30cm (12in) apart. Seed sown outdoors usually flowers the year after sowing. Thin out so that there is one good plant every 6cm (4in). The thinnings can be transplanted.After harvesting the main head, secondary heads will appear and these too can be used. In cold areas, cover the plant with a mulch of straw, compost or bracken to protect it through the winter.