Sowing Time: March to May. Sow in pots or trays of moist seed compost and cover with a very fine sprinkling of compost or vermiculite. Place in a propagator or warm place, and keep at a constant temperature of between 20-25C (68-77F). After sowing, do not exclude light as this helps germination. Keep the surface of the compost moist but not waterlogged; germination will usually take 10-21 days.
Can also be sown once the soil has warmed, 3mm (1/8in) deep in drills 30cm (12in) apart in well-cultivated soil which has been raked to a fine tilth. When large enough to handle, thin out seedlings to 23cm (9in) apart.