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.

Water regularly in hot, dry weather, especially for plants in containers, and deadhead faded blooms frequently to keep the display going for longer. Choose a sunny, sheltered spot outdoors as these sun-lovers flower best with plenty of light. Avoid overly rich compost, which can encourage lush growth at the expense of flowers.

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.