Using a good quality, moist seed compost, sow your seeds in a propagator by pressing the seed gently into the surface of the compost, and cover with 3mm (1/8") compost. Place on a windowsill or in a greenhouse at approximately 15-20°C (60-68°F) to germinate (usually 10-14 days). Space seedlings 5cm (2") apart in trays and grow on. Acclimatise before planting out 18cm (7") apart after danger of frost has passed. Alternatively, sow direct in a sunny position 6mm (¼") deep and cover with soil. Thin resulting seedlings gradually to 18cm (7") apart.