If your daylilies have been looking a little lackluster this summer—fewer blooms, maybe a bit overcrowded—it might be time to face the truth: they need more space. These low-maintenance, sun-loving perennials are garden favorites across the U.S. and Europe, known for their trumpet-shaped flowers and reliable blooms. But even the toughest plants need a reset now and then.
Cathy Rees, a seasoned gardener in Maine, has grown more varieties of daylilies than she can count. Every spring or late summer, she rolls up her sleeves, digs up the overgrown clumps, and gives them a fresh start. “It’s like getting kids out of bunk beds and into their own rooms,” she jokes.
Like many perennials—think hostas, irises, and asters—daylilies benefit greatly from division every three to five years. If left alone, their roots become tangled and overpacked, which can choke off nutrients, invite disease, and lead to fewer flowers year after year.
So, when’s the best time to divide them? While spring is ideal, late summer works too—if you act fast. Sharon Yiesla, a plant knowledge specialist at the Morton Arboretum in Illinois, advises gardeners not to wait too long. “You want to divide after blooming stops but at least four weeks before your area’s first frost,” she says. That gives the plant time to recover and re-establish before winter sets in.
If you missed the early spring window, now’s your last solid chance.
Here’s how to do it right—and give your daylilies a second wind.
Start the day before by giving your plants a thorough drink. This softens the soil and helps roots stay hydrated through the process. Then, choose a cool, overcast day—ideally just before some light rain. Conditions like this help minimize transplant shock.
You can dig up the entire clump, shake off excess soil, and slice it cleanly with a garden knife. Or, if you prefer a gentler approach, do what Cathy does: dig about six inches from the plant crown on just one side, and carefully slice off a section without disturbing the rest. Either way, the goal is to create smaller clumps that each have a healthy root system and at least two to three leafy “fans.”
Worried about cutting through roots? Don’t be. As long as each division has a solid root base and some green growth, it’s resilient enough to bounce back.
Once divided, replant your daylilies in a sunny, well-drained spot—six hours of light a day is a good baseline. Dig holes slightly larger than the root ball, mix in some compost if your soil is tired, and plant so the crown sits just below the surface. Firm the soil, water deeply, and add a layer of mulch around the base to lock in moisture.
If you're dividing in fall, trim the leaves down to about six inches. Spring divisions don’t need trimming if the leaves are still short.
As for fertilizer? No rush. These plants are pretty self-sufficient. Regular watering is more important in the weeks after transplanting. But if you want to give them a gentle boost, consider a diluted organic fertilizer—like liquid seaweed or fish emulsion—once they've started to settle.
Mark Jensen, a backyard gardener in Minnesota, grows nearly 20 different types of daylilies in his yard. After each division session, he gives the extras to his neighbors. “They’re the perfect gift—beautiful, low-maintenance, and personal,” he says. “And honestly, it’s a great excuse to knock on someone’s door.”
So if you haven’t touched your daylilies in years, don’t wait for spring. Grab your shovel, give your garden a refresh, and enjoy the rewards next season. After all, sometimes the best thing you can do for your plants—and yourself—is to make space for something new.