Prune Osteospermum plants in the early spring to prepare them for summer flowering. Remove any dead or unsightly flowers by using your garden shears to cut the stems back just below the head of the flower.
Trim new Osteospermum plants by pinching off the top layer of leaves off with your fingers. Do not trim beyond the second layer of leaves.
Prune the side branches on older Osteospermum plants by snipping off the side leaves and growth without severing the side branches themselves. This will allow new growth to come in much more fully.