Pot up seedlings and cuttings and grow on under glass until all risk of frost has passed and they can then either be planted outside into a well-prepared bed, or used to fill decorative pots and hanging baskets for the patio. Pinching out the growing tips will encourage them to become bushier, and feeding with a high-potash fertiliser at regular intervals throughout the summer will promote even more flowers to form. Although usually grown as an annual, plants that are protected with a dry mulch may survive mild winters where temperatures only occasionally fall below -5°C (23°F).