Indoors sow February to March, thinly in pots or trays of seed compost. Gently firm the seeds into the surface. Keep moist and warm, approx. 15-20oC (60-68oF). When large enough transplant 5cm (2in) apart in further trays. Grow on at approx. 15oC (60oF). Gradually harden off before planting out to final position in late May spacing 30cm (12in) apart.
Outdoors sow April to June in a seed bed, cover lightly with fine soil and keep moist. When large enough thin to 10cm (8in) apart. Transplant to flowering position September to October.
Flowers: May to September, the following year. Remove dead heads to prolong flowering.