The daylilies in our garden beds are beginning to crowd out other plants. Can they be separated and thinned out?
Experts at the National Arboretum and the American Hemerocallis Society Society suggest thinning clumps of daylilies every five years or so. Repeat blooming varieties (such as ‘Stella de Oro,’ ‘Happy Returns’ and others) tend to form larger clumps, and may need to be divided more often. Early spring and fall are good times to take care of this task.
When the time comes to divide the clumps, use a garden fork to loosen the soil and pry the clump of roots out of the ground. Divide it by pushing two garden forks back to back down into the center of the clump, then push the handles apart to separate the roots.
To replant the divisions, dig a wide, shallow hole and place the rootball into the hole. Backfill with soil and tamp it into place, then cover the soil with an inch of mulch. Water thoroughly. You can cut the foliage back to about 12 inches.
(Stella de Oro? Stella d’Oro? You may see it spelled either way. I use the same spelling as the American Hemerocallis Society, which provides loads of information about daylilies at its website.