We recommend growing your polyanthus plants indoors until they reach 8 to 10cm in height at which point, they’ll be ready to plant outdoors making sure they are planted in moist and well drained soil.
If you choose to grow your polyanthus in a container, fill the pot or basket up to three-quarters full 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.
For open planting, dig a hole with a trowel to the same size as the plant’s root ball, and place the plant in position. Fill in the hole and gently firm down the soil and water immediately making sure to plant the polyanthus so that their crown is at soil level and to leave a 10 cm gap between each plant.