Sow at 18-21C in a good seed compost just covering the seed with compost. Germination usually takes 10-21 days. When seedlings are large enough to handle, transplant 5cm apart in boxes or into 7.5cm pots and grow on in cooler conditions. Gradually acclimatise to outdoor conditions for 10-15 days before planting out after all risk of frost, 23cm apart in full sun in ordinary well drained soil. For summer flowering pot plants, baskets and containers transplant the seedlings into 7.5cm pots, grow cool, well ventilated and water freely, plant up the baskets in May and harden off well before hanging outside.