One of the best features of day lilies is that they can be propagated by dividing the roots and replanting the separated portions. Typically done in the spring or fall, you can separate day lilies every four to six years without having to worry about collecting seeds and germinating them. By dividing your day lilies, you also ensure that you are getting a pure strain of a specific variety without cross-pollination from other varieties.
Select the day lily plant you need to separate. Examine the clump of shoots to see where the innermost portion is, and look for outer sections with about three shoots coming off them.
Push the spade straight down to cut the segment loose from the mother clump. You can cut off more sections of three shoots each as long as the center remains intact.
Pull the sections from the soil with your hands without disturbing the center clump. Cut pieces that are still connected with your spade, or pull stubborn sections from the clump with your spading fork.
Plant your separated sections 2 feet apart in similar soil and sun. The crown of the plant--the space where the foliage and roots meet--should rest 1 inch below the soil surface.
Water your new plants twice a week for the first few months.