Sow with warmth provided from early spring under cover or in an unheated greenhouse from May onwards  for outdoor displays.  Can be sown inside for the window sill at any time.
Can be sown direct to plugs or an inch apart for later transplanting.
The seeds should be only lightly pressed into the growing medium as they need light to germinate.  Please note the seed is tiny / extremely fine.
Germination in the correct conditions takes 7-10 days.
For seeds started in trays transplant when the first 2 sets of true leaves have formed, about 10 weeks after sowing.
The plants may develop flowers which are best removed immediately to concentrate the plants energy on the foliage.  Pinch out shoots early to develop bushy habit.