Sow seeds indoors in a soilless mix 5 to 6 weeks before the last frost date. Sow seeds 6 mm (1/4 in) deep and store at 20°C (70°F) for the germination period of 7 to 10 days. Grow at a slightly cooler temperature, then harden off and plant outdoors in late May.
Space plants 45 cm (18 in) apart in rows 75 cm (30 in) apart. Spring to summer crops will not form dense heads. For best results, plant in late summer for fall harvests. Optimal growing conditions are cool weather of 12 to 21°C (55 to 70°F) with cool to cold nights of 4 to 10°C (40 to 50°F).
