Reliable and durable perennials, daylilies (Hemerocallis) quickly multiply into massive clumps of plants, called fans. If overcrowded, their vigor and summer floral display wane. Digging up plants and replanting smaller clumps of plants with ample spacing between them allows regrowth and added vigor. Tackle the division of the daylilies after they finish blooming; if they are so overcrowded that they no longer flower, divide them in early spring as new growth emerges, although late summer is still ideal.
Things You’ll Need
- Potato fork
- Dig up the crowded clump with a garden shovel in late summer (August is perfect). Wedge the shovel blade into the soil 6 inches away from the base of the clump, making cuts all the way around it. Lift any weeping foliage blades to see the base of the plant if needed.
- Lift the root ball of the clump and let it rest on its side on the ground. Remove any dead leaves to better visualize all the plants, or fans, in the mass.
- Slice the root ball with the shovel blade, cutting into the soil as the clump lies on its side. Try to position the blade so it slices in between masses of roots and fans to diminish damaging plants. As you break up the root ball into three or four smaller clumps, you may cause some damage. Use a potato fork to break apart the root ball if the shovel does not penetrate easily.
- Pull apart the root ball once sliced. Remove any cut foliage or obviously cut and damaged roots and tubers. The clumps created by splitting up the root ball should be about softball or grapefruit-size, with two to four fans in each.
- Replant the small clumps in the garden bed, matching their root ball height to the natural soil line in their holes. Place each clump 12 to 18 inches away from each other so there is ample room both above and below ground for the daylilies to grow for the next three to fous years.
- Repeat steps 1 through 5 with all densely clumped areas of plants in the daylily garden until there is no less than 12 inches between all larger plant clumps, untouched or transplanted.
- Cut back the foliage of the daylilies 50 percent with pruners or scissors. This reduction of leaves reduces water loss and diminishes strain on the roots to sustain above-ground growth. The roots should be multiplying and establishing before the winter.
- Water the daylilies to moisten their roots and remove any air pockets in the soil. Spray or sprinkle 1 to 2 inches of water over the area. Allow natural rainfall to sustain the plants the remainder of the growing season unless you feel conditions are overly dry from lack of rain.
Tips & Warnings
If your daylilies no longer flower, divide clumps in early spring when the new growth is no taller than 2 inches. The soil will be chilly to work, and as long as the soil is watered after transplanting, the plants should grow well. Expect the daylilies to flower the following year.
Thin out plant clumps every three to five years to maintain healthy, vigorous and abundantly flowering daylilies.
Do not plant daylilies in areas with less than six hours of direct sunlight. Too little light impedes flowering.
Avoid overly dry or soggy soils. Although drought tolerant, these perennials perform much better if the soil is moist and well-draining.