Sowing – 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.

Growing – When seedlings are large enough to handle, transplant and grow in cooler conditions. Gradually acclimatise to outdoor conditions for 1-15 days before planting out after all risk of frost, 3cm (12in) apart in a sunny spot.

Flowers – June to September