The plants grow 150mm -500mm (6"-18") high subject to variety.
It flowers from roughly mid June until the frosts cut it down.
bonariensis is a clump forming perennial ideal for adding height to a border.
Week 6: Sow bonariensis varieties early and hopefully they will flower in their first year.
Week 12: Sow annual varieties in pots / trays of seed compost and germinate at a temperature of 18°- 21°C (65°- 70°F)
Germination should take about a week.
Week 15: If large enough to handle, prick out seedlings in cell trays or boxes and gradually harden off in a frost free cold frame until planting out time.
Week 21: Plant out annuals in fertile, well-drained soil 150-200mm (6"-8") apart and bonariensis 500-600mm (18"-24") apart.