Ornamental · Asphodelaceae
Daylily
Hemerocallis fulva
Easygoing and fast to settle in, the daylily trades a sunny spot for a fresh bloom every morning all summer.
Full sun
Every 7–14 days
USDA 3–9
2–6 ft · 0.8–1.8 m
Overview
Ever wonder how the daylily got its name? Each flower opens at dawn and is done by dark, and the next morning a new one takes its place on the same scape. It's a clumping perennial that started out in Asia and now grows pretty much everywhere temperate, looking right at home in a tidy border or running wild down a roadside ditch. Honestly, few plants ask for less.
It grows from thick, fleshy roots that push up arching, grass-like leaves and tall stalks holding the flowers all through summer. The plain orange fulva travels fast by rhizome and can take over a spot, but the named hybrids stay where you put them and come in just about every color except true blue. And here's a fun part: the flowers and buds are edible, with a sweet, mild taste.
There's one thing you can't skip, though. Daylilies are deadly to cats, and even a tiny taste of leaf, flower, or pollen can shut down a cat's kidneys. So if a cat lives with you, think it over carefully before you plant, and don't ever bring cut daylilies inside.
Care
The short version: full sun, average well-drained soil, a moderate drink while it's growing, and a clump split every few years so the flowers keep coming.
Light
Daylilies flower best in full sun, so 6 or more hours a day is the sweet spot. They'll put up with partial shade, sure, but when light's short they tend to stretch and you'll get fewer blooms.
Water
Give them a moderate, even drink through the growing season, roughly every 7 to 14 days once they're settled in. They handle dry spells better than most perennials, so a missed watering isn't a crisis, but steady moisture is what gets you the heaviest flush of flowers.
Soil
Just about any well-drained loam works, and a little organic matter helps too. They're happiest at a pH of 6.0 to 7.0, though they'll still manage in poor or heavy clay ground that would stop fussier plants in their tracks.
Humidity
There's nothing to track here, since ordinary outdoor humidity is all they want. What does help is good airflow around the crown, because the rots that bother daylilies like it warm, still, and damp.
Feeding
Daylilies are light feeders, so they don't need much. One dose of balanced general-purpose fertilizer in spring usually carries a planting right through the season.
Pruning
Deadhead the spent flowers each day to keep things looking neat, and cut the flower scapes down once the blooms are finished. When the foliage dies off, trim it back in late fall or early spring before new growth shows up.
Size & spacing
Depending on the variety, they grow 2.5 to 6 feet (76 to 183 cm) tall and form clumps 24 to 30 inches (61 to 76 cm) wide. Give each one a bit of room so air can move freely around the crown.
When to plant
Daylilies are hardy perennials for zones 3 through 9, so they'll come back on their own year after year. Pop new plants in during spring or early fall once hard frost is gone, and the flowers should hit their peak across July and August.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Not typically grown from seed by home gardeners; hybrids do not come true from seed.
- Plant: Spring or early fall, after the danger of hard frost has passed.
- Harvest: Summer, roughly July to August in the temperate northern hemisphere.
Hardiness
USDA hardiness zones: 3–9
Temperature: down to -40°C
Troubleshooting
Good news here: daylilies are about as trouble-free as a perennial gets, and most of what goes wrong is just cosmetic. Spot something off? Match it to the notes below and deal with it before it spreads through the clump.
The crown rots and caves in during warm, sticky weather
When it's hot and muggy, southern blight can show up, rotting the crown and laying a white web of threads over the soil with tan, seed-sized sclerotia mixed in. There's no saving a plant once it's infected. Dig it out along with the soil around it, then sort out the drainage and keep mulch pulled back from the crown so it doesn't come back.
Fix:
- Remove and destroy infected plants and surrounding soil
- Improve drainage and air circulation
- Avoid burying the crown too deeply
Older clumps get crowded and bloom less over time
Daylilies spread fast by rhizome, so after a few seasons a clump can get so packed that the middle thins out and the flowers taper off. The fix is easy, though: division. Lift the clump in early spring or right after bloom, split it into fans, and replant each one with the crown sitting at soil level.
Fix:
- Dig and divide the clump in early spring or after bloom
- Replant divisions with the crown at soil level
Squiggly pale trails wandering across the leaves
That's the daylily leafminer at work, a little larva that eats inside the leaf and leaves those winding mines behind. Hold a leaf up to the light and you can actually see the trails. It looks worse than it is, honestly, and it won't kill an established clump, so just pull off the badly mined leaves and let the plant keep going.
Fix:
- Remove and destroy heavily mined leaves
- Maintain plant vigor with adequate water and division
Toxicity
If there's a cat in the house, read this bit closely. Daylilies are deadly to cats, and swallowing any part, even pollen they've licked off their fur or a sip of vase water, can cause fatal kidney failure within hours. Dogs and horses get off a lot lighter, and people can actually eat the flowers, but for a cat there's just no safe amount.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Severe
For a cat, this is the real deal, a true emergency. Even a nibble of leaf or flower, a lick of pollen off the fur, or a sip of vase water can set off acute kidney failure, and it can turn deadly within hours. You'll usually see vomiting first, then a refusal to eat and growing lethargy, which slide into full renal shutdown. Get the cat to a vet right away, because treatment only works if it starts early.
Dogs Mild
Dogs come out of this a lot better than cats do. A dog that chews on the plant might drool or have a quick bout of vomiting or loose stools, but it doesn't face the kidney danger that makes daylilies so deadly to cats.
Horses Mild
For horses, nibbling the foliage usually causes nothing worse than a mild stomach upset, maybe a little drooling or loose manure if they really go to town on it.
Rabbits Caution
Nobody's really documented how daylilies hit rabbits, so it's safest to treat the plant as off limits and not let a rabbit graze the foliage or flowers.
Livestock Caution
There isn't much solid data on grazing animals, so keeping cattle, goats, and sheep away from daylily stands is just the sensible move rather than risking an untested plant.
Birds Caution
How it affects pet and backyard birds hasn't been studied, so keep cuttings and pollen out of reach until somebody knows more.
People Flowers edible
For people, the flowers and buds are edible, sweet and mild, and cooks have used them for ages, so they're safe to eat in moderation. But that's never a reason to relax around cats, who can be killed by any contact at all.
A feline emergency: keep all parts of the plant, fallen pollen, and any cut-flower water completely away from cats.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
There are tens of thousands of registered hybrids, which is kind of wild, but only a few species and old favorites really anchor the group. These are the ones worth knowing first.
Hemerocallis fulva (Orange / Tawny daylily, 'Ditch lily')
This one spreads fast by rhizome, throws rusty-orange unscented blooms, and has gone wild along roadsides all over North America, which is exactly how it picked up the nickname ditch lily.
Hemerocallis fulva 'Kwanso'
It's a double-flowered form loaded with extra petals and no working stamens, so it sets no seed and only spreads by its rhizomes.
Hemerocallis lilioasphodelus (lemon daylily)
An early bloomer with fragrant clear-yellow flowers, it's a real contrast to the unscented orange of the common fulva.
Hemerocallis 'Stella de Oro'
A compact hybrid that reblooms all season, it keeps sending up wave after wave of golden-yellow flowers.
How to propagate
Want more daylilies? They multiply easily, and division is really the only method most gardeners ever need to fill a whole bed from one clump.
DivisionEasy
Early spring as new growth emerges, or in fall after blooming has finished. · Divisions typically reestablish and resume strong growth within one growing season, often blooming the following year.
If you want more daylilies, division is the way to go. Do it in early spring as new growth pushes up, or in fall once the flowers have faded. Just dig the clump, pull it apart into fans that each hold roots and a crown, and set them back at the depth they were. They spread fast by rhizome and usually settle in within one season, often blooming again the next year.
Myths
Daylilies are true lilies, so they've got to be just as risky to cats as any other lily.
Here's the thing: daylilies are Hemerocallis, which sits outside Lilium, the true lily genus, so the botany really is different. The danger? Exactly the same, unfortunately. Both cause acute kidney failure in cats and have to be kept well away from them.
Daylily flowers are poisonous to people just like they are to cats.
Not for people, actually. The flowers and buds are edible, with a sweet, mild flavor that's earned them a spot in the kitchen for centuries. That doesn't say a thing about cats, though, since even a small exposure can be fatal for them.