A gardener will know it is time to split daylilies when the daylily leaves become less robust and the number of flowers declines. Daylilies are resilient perennial flowers that will reward your work to split them by coming back healthier and happier than ever. In late summer after the daylilies have finished blooming for the season, divide daylilies to renew their vitality and improve their blooming.
Use the rake to remove mulch and other debris from the daylily growing area. Spread out the tarp near your work area.
Position the tines of a garden spade approximately 10 inches outside of the edge of the daylily clump. Push the tines into the ground to loosen the clump in the soil. Remove the spade and reposition it at another spot approximately 10 inches outside of the daylily clump. Push the spade tines into the soil again to loosen the clump. Repeat this around the entire perimeter of the clump to loosen it completely from the soil.
Lift the daylily plant out of the soil with the spade and place it on the prepared tarp. Find the middle of the clump and insert both spades with backs facing each other into this spot. Push the spade handles away from each other to break the clump into two pieces. Repeat this with both separated pieces if you want still smaller clumps.
Dig holes for the newly divided clumps that are a little less than the measurement of the entire root ball for shallow planting. Make the holes approximately 8 inches wider than the root balls.
Place the daylilies into the prepared holes and fill the soil back in around the roots. Press the soil firmly around the roots. Water the daylilies generously.
Add shredded mulch in a 1-inch layer around the base of the daylily plants to keep the soil moist and to deter weeds. Trim off the daylily foliage to approximately 12 inches.