Ornamental · Asphodelaceae
Daylily
Hemerocallis fulva
Tough, fast, and almost foolproof, the daylily rewards full sun with a summer of fresh blooms every morning.
Full sun
Every 7–14 days
USDA 3–9
2–6 ft · 0.8–1.8 m
Overview
The daylily earns its name honestly: each flower opens at dawn and is spent by nightfall, replaced the next morning by another on the same scape. It is a clumping perennial that traces back to Asia and now grows across most of the temperate world, just as comfortable in a tidy border as gone wild along a roadside ditch. Few garden plants ask for less.
Grown from thick, fleshy roots, daylilies push up arching grass-like foliage and tall flower stalks that carry their blooms through the heart of summer. The common orange fulva spreads fast by rhizome and can take over, while named hybrids stay where you put them and come in nearly every color but true blue. The flowers and buds are also edible for people, with a sweet, mild taste.
One thing matters above all else with this plant. Daylilies are deadly to cats, and even a small taste of leaf, flower, or pollen can shut down a cat's kidneys. If a cat shares your home, weigh that hard before planting, and never bring cut daylilies indoors.
Care
The short version: full sun and average, well-drained soil, a moderate drink during the growing season, and a clump split every few years to keep the flowers coming.
Light
Daylilies flower best in full sun, ideally 6 or more hours a day. They put up with partial shade, but in too little light the plants stretch and the bloom count drops off.
Water
Give a moderate, even drink through the growing season, watering every 7 to 14 days once the plant is established. Daylilies shrug off dry spells better than most perennials, yet steady moisture is what brings the heaviest flush of flowers.
Soil
Almost any well-drained loam suits them, and a dose of organic matter helps. They run best at a pH of 6.0 to 7.0 but still cope with poor and heavy clay ground that would stall fussier plants.
Humidity
Ordinary outdoor humidity is all they ask, so there's no number to manage. Good airflow around the crown does more good, since the rots that trouble daylilies take hold in warm, stagnant damp.
Feeding
Daylilies are light feeders and don't need much. A single dose of balanced general-purpose fertilizer in spring carries most plantings through the season.
Pruning
Deadhead the spent flowers daily to keep the clump looking clean, and cut the flower scapes down once bloom is over. Trim back the dead foliage in late fall or early spring before new growth starts.
Size & spacing
Plants reach 2.5 to 6 feet (76 to 183 cm) tall, depending on the variety, and form clumps 24 to 30 inches (61 to 76 cm) across. Give each one room to spread so air moves freely around the crown.
When to plant
Daylilies are hardy perennials suited to zones 3 through 9, so they come back on their own year after year. Set new plants out in spring or early fall once hard frost has passed, and expect the show to 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
Daylilies are about as trouble-free as a perennial gets, and most issues are cosmetic rather than fatal. Match what you see below to act before a minor problem spreads through the clump.
The crown rots and collapses in warm, humid weather
Southern blight strikes in hot, muggy spells, rotting the crown and laying a white web of threads across the soil with tan, seed-sized sclerotia scattered through it. There is no saving an infected plant. Dig it out along with the dirt around it, then fix the drainage and keep mulch pulled back from the crown so it doesn't return.
Fix:
- Remove and destroy infected plants and surrounding soil
- Improve drainage and air circulation
- Avoid burying the crown too deeply
Older clumps crowd up and bloom less each year
Daylilies spread fast by rhizome, and after a few seasons the clump packs so tightly that the center thins and flowering drops off. The cure is simple division. Lift the clump in early spring or right after bloom, split it into fans, and replant with the crown at soil level.
Fix:
- Dig and divide the clump in early spring or after bloom
- Replant divisions with the crown at soil level
Winding pale tunnels traced through the leaves
This is the daylily leafminer, whose larvae feed inside the leaf and leave squiggly mines behind. Hold a leaf up to the light and you can see the tracks. The damage looks worse than it is and won't kill an established clump, so just strip off the badly mined leaves and keep the plant growing strong.
Fix:
- Remove and destroy heavily mined leaves
- Maintain plant vigor with adequate water and division
Toxicity
Read this part carefully if you keep cats. Daylilies are deadly to cats, and swallowing any part, even pollen groomed off the fur or a sip of vase water, can cause fatal kidney failure within hours. The plant is far gentler on dogs and horses, and the flowers are actually edible for people, but for a cat there is no safe amount.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Severe
This is a true feline emergency. Even a nibble of leaf or flower, a lick of pollen off the fur, or a sip of vase water can trigger acute kidney failure, and it can turn deadly within hours. The first signs are vomiting, a refusal to eat, and growing lethargy, which slide into full renal shutdown. Get the cat to a vet at once, because treatment only works when it starts early.
Dogs Mild
Dogs get off far more lightly than cats. A dog that chews on the plant may drool or have a brief bout of vomiting or loose stools, but it doesn't carry the kidney danger that makes daylilies so deadly to cats.
Horses Mild
Grazing on daylily foliage tends to cause no more than mild stomach upset in horses, with a little drooling or loose manure if they eat much.
Rabbits Caution
How daylilies affect rabbits isn't well documented, so treat the plant as off limits and don't let a rabbit graze on the foliage or flowers.
Livestock Caution
There's little firm data on grazing animals here. Keep cattle, goats, and sheep away from stands of daylily as a sensible precaution rather than risk an untested plant.
Birds Caution
The effect on pet and backyard birds is unstudied, so keep cuttings and pollen out of reach until more is known.
People Flowers edible
The flowers and buds are edible for people and have a sweet, mild taste, long used in cooking. That makes the plant safe to eat in moderation for humans, but never a reason to relax around cats, for whom any contact can be fatal.
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
Daylilies run into the tens of thousands of registered hybrids, but a few species and old favorites anchor the group. These are the ones worth knowing first.
Hemerocallis fulva (Orange / Tawny daylily, 'Ditch lily')
This vigorous, rhizome-spreading species throws rusty-orange unscented blooms and has naturalized so widely along roadsides across North America that it earned the nickname ditch lily.
Hemerocallis fulva 'Kwanso'
A double-flowered form packed with extra petals and no working stamens, it sets no seed and spreads only by its rhizomes.
Hemerocallis lilioasphodelus (lemon daylily)
An early bloomer carrying fragrant clear-yellow flowers, a sharp contrast to the unscented orange of the common fulva.
Hemerocallis 'Stella de Oro'
A compact hybrid that reblooms all season, sending up wave after wave of golden-yellow flowers.
How to propagate
Daylilies multiply easily, and division is the only method most gardeners need to fill a bed from a single 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.
Division is the way to multiply daylilies, done in early spring as new growth pushes up or in fall once the flowers fade. Dig the clump, pull it apart into fans that each keep roots and a crown, and set them back at the original depth. They spread fast by rhizome and usually settle in within a single season, often blooming again the next year.
Myths
Daylilies are true lilies, so they pose the same danger to cats as any other lily.
Daylilies belong to Hemerocallis and sit outside the true lily genus, Lilium, so the botany is genuinely different. The danger, though, is identical. Both cause acute kidney failure in cats and must be kept well away from them.
Daylily flowers are poisonous to people the way they are to cats.
The flowers and buds are edible for humans, with a sweet, mild flavor that has earned them a place in the kitchen for centuries. That says nothing about cats, for whom even a small exposure can be fatal.