Begin sowing the seeds indoors from March-April or September-October. Scatter the seeds thinly on the surface of damp seed compost and lightly cover. Keep trays in a propagator or cover with clear polythene, maintaining a steady temperature of around 17-20°C. Place the seeds somewhere dark until germination, which usually takes 10–20 days. If there’s no germination after 20 days then cold stratify for 6 weeks. When seedlings reach about 5cm tall, move them carefully into individual pots or modules. Harden plants off gradually by exposing them to outdoor conditions for short periods. Transplant into borders, baskets, or containers once frosts are no longer a risk (late spring to early summer). Feed regularly with a balanced liquid fertiliser to support healthy growth and prolonged flowering.
