Sow in spring at 21-24C (70-75F) in a good seed compost. Just cover the seed with compost and keep the soil damp but not wet. Germination usually takes 5-14 days.
When seedlings are large enough to handle, transplant and grow in cooler conditions. Gradually acclimatise to outdoor conditions for 10-15 days before planting out after all risk of frost, 6-8in apart in a sunny spot.