Martin offers these instructions to divide daylily plants:
l Dig up an overgrown daylily clump and separate it with a sharp knife or spade. Discard any unhealthy sections. In summer, trim the leaves of a divided clump to allow the plant to establish a strong and healthy root system.
l Dig a hole about 12 inches to 14 inches in diameter and depth for the newly divided daylily.
l Pile a cone of soil in the center of the hole. Place the plant atop the cone so that the roots radiate outward and do not crowd each other.
l Replant to the same depth as the original plant.
l Refill the hole with soil and water well. Newly divided and transplanted daylilies should be watered weekly with an inch of water.