Although day lilies are tough enough to be divided in the summer months, why disrupt your garden while they are blooming? Waiting until after the flowers are gone makes more sense. If your day lilies were under-performing this year, or seem very crowded, dividing these perennials will entice them to produce more flowers.
Why Divide Perennials? There are three primary reasons for dividing perennials: to control the size of the plants; to help rejuvenate your plants; and to increase the number of plants you have. This is an inexpensive way to gain additional plants for your garden (or to share with others). When Should You Divide Perennials? This … How and Why to Divide Perennials