Sow seeds directly outdoors in a sunny site with good soil in late May. In zones 6 and above, re-sow from mid-August to mid-September. In spring, seeds can also be started indoors in a soilless mix 6 to 8 weeks before the last frost date. Maintain temperatures at 70°F (21°C) for the 14-21 day germination period, then grow at a slightly cooler temperature before hardening off and transplanting outdoors once danger of frost has passed.
Sow seeds 6mm (1/4in) deep and 2cm (3/4in) apart, then thin out shoots 60-90cm (24-36in) apart in the garden.
