When planting outdoors, dig an individual hole for each plant - the hole should be deep enough to cover the roots, but not any of the exposed stem. Gently firm into the ground and water in. Keep watering throughout the season and feed weekly for the best results.
For container planting, fill the container up to three quarters with multipurpose compost. Carefully remove the plant from the tray or pot and place in position. Fill the container back in with soil and gently firm down. Water in generously. Leave a space of 10 cm between plants when planting into a bed.
Good to know: Extreme heat will cause the plants to suffer and flower less.