Sow undercover in fine seed compost with warmth from 8-10 weeks before the last frost.
Barely cover the seeds, just pressing into the growing medium as these need light to germinate.
Germination Temp ? 18-24c. If minimum temp not maintained germination will be poor / sporadic.
When large enough to handle pot on to 8cm pots.
Gradually acclimatise to outdoor conditions before planting out after all danger of frost has passed.
Happy in most soils, plant in Full sun 30cm spacing