The variety of flower colours, include white, pink, red, blue, lavender and yellow, thus making it a useful plant for informal plantings in open sunny spots.
The dwarf types are just 150-200mm (6"-8") tall, whereas the taller varieties can reach 400-500mm (14"-18").
Some of the lower growing varieties are suited to baskets and containers.
The flowers appear in July and go on into October if regularly deadheaded.
When watering, avoid wetting the leaves as this can promote fungal disease.
Feed monthly with a water-soluble fertilizer if rewquired.
Week 13: Sow seed in pots/trays of seed compost, and germinate at a temperature of 20°C (68°F).
Germination should take about a week.
Week 16: Prick out the seedlings into cell trays of potting compost then gradually harden off in a cold frame till planting out time.
Week 21: Plant out 150-200mm (6"- 8") apart in a well drained fertile sunny site.
Pinch out the growing tip at planting time to encourage bushier growth.