The performance of some perennial all-stars fades when they grow into dense, often unattractive clumps. Now is a good time to dig and divide to rejuvenate these plants and use the cuttings around your garden. Some candidates include daylilies (in inland gardens), alstroemerias, clivia, agapanthus (preferably late in the month), fortnight lily (Dietes) and iris. All have fleshy roots and shallow root balls. Dig them up and divide the clumps with a sharp knife or shovel. Then replant immediately. Other perennials to divide now include yarrow, verbena, African daisy (Arctotis), gazanias, ivy geraniums and dianthus. Cut through the clumps with a sharp shovel going deep enough to retrieve a good amount of roots. Then replant. Time digging and dividing to coincide with a cool spell and water the cuttings regularly to help them become established.