Daylilies grow throughout the U.S. and in most of the temperate areas of the world. More than 35,000 varieties of daylilies are registered species, and hybridizers continue to develop new varieties. After three or four years' growth, daylily rhizomes form dense clumps. The clumps must be divided, or the center of the clump will begin to die. Daylilies are easy to divide and transplant. This increases the number of plants in your garden, while it rejuvenates your daylily beds.
Select a location with well-drained soil that receives full sun six to eight hours a day. Daylily plants can survive in partial shade, but the color and number of blooms is diminished. Anytime during the growing season is a good time to transplant daylilies: spring, summer or fall.
Dig the soil with a shovel, garden fork or tiller. The soil should be tilled 8 to 12 inches deep to allow good root development. Work the soil until it is finely pulverized, mixing in compost to add humus and organic nutrients. Daylilies grow best in soil with slightly acid or neutral pH near 6.5 or 7.0.
Lift a clump of daylilies with a garden fork. Pull the rhizomes and crowns apart, using a knife to separate the plants, if necessary. Each separated plant must have a rhizome, roots and leaves.
Set the plants into the prepared soil, spacing them 12 inches apart. Firm the soil. The crown of each plant should be 1 inch below the soil surface.
Water the transplanted daylilies immediately. Keep the new plants watered deeply to encourage strong root systems.
Apply a layer of organic mulch to keep weeds down and retain soil moisture. Organic matter slowly decomposes and provides nutrients. Chopped leaves and dried grass clippings make ideal organic mulch.
Peat creates a mat that water can't penetrate; it is not recommended as mulch.