The flowering period is from mid-late July until the first frosts.
They can be grown anywhere so long as it's in a sunny spot.
For best results incorporate plenty of well rotted organic manure into the soil before sowing and / or planting.
Remove spent flowers regularly to prolong the flowering season.
Week 8: Sow seeds onto the surface of fine moist seed compost, and cover with a fine dusting of vermiculite.
Place into a heated propagator or simply cover with a sheet of glass or place in a plastic bag and maintain a temperature of 18°-20°C (65°-68°F)
Keep in a light place until the seeds germinate, usually about two weeks.
Once germinated, remove the lid of the propagator or remove the container from the plastic bag and grow on until large enough to handle.
Week 15: When large enough to handle, prick them out into 50-75 mm (2"-3") cells / pots and grow on in well lit cooler conditions, gradually hardening them off till planting out time.
Week 22: When all risk of frost has passed,plant out 300mm (12") apart* in a sheltered spot into fertile well drained soil and full sun.
* 150mm (6") between plants in containers.
Week 35-40: As an alternative, sow seeds now and over winter under glass to hopefully get flowers in early June the following year.
Keep these sowings at 10°-13°C (50°-55°F) throughout the winter in good light and keepwell ventilated.
Water carefully! Do not allow the soil to become saturated.