Many perennials that are clump forming such as agapanthus, daylilies, irises and kangaroo paws can be successfully divided in late winter, just before the new spring growth. Lift the clumps from the ground with a garden fork or spade and shake off most of the soil. Cut away dead flowers and leaves and pull the clumps apart if possible (an old bread knife is a good tool if the clumps cannot be easily separated). The best results will be achieved by retaining at least 3 shoots in the divided pieces. Cut the foliage in half to reduce the water stress after replanting. The new clumps can go straight back into the garden but a better result is often obtained by allowing them to re-establish in pots in a sheltered position until they are showing signs of new growth.