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 place on a windowsill or in a greenhouse at approximately 15-20°C (60-68°F) to germinate (usually 10-21 days). Do not exclude light. Transfer seedlings into seed trays and grow on, spacing them 5cm (2") apart. Plant out 40cm (16") apart in a sunny position. Sow January-May under glass in gentle heat for flowers June-October, or sow July-September in a cold frame for planting the following spring.