Ornamental · Asphodelaceae
Daylily
Hemerocallis fulva
Arching blades and tall stalks crowned with bloom, the daylily unfurls a fresh flower every morning through summer.
Full sun
Every 7–14 days
USDA 3–9
2–6 ft · 0.8–1.8 m
Overview
The daylily wears its name in each flower, and the flower is the thing to watch. A single bloom unfurls at dawn, its petals spreading wide and flushed with color, then folds and withers by nightfall, while the next bud on the same scape swells to take its place by morning. The plant grows as a tight clump, a perennial out of Asia now spread across the temperate world, the same arching shape whether it stands in a trim border or sprawls along a roadside ditch. The form barely changes from one setting to the next.
Underground, thick and fleshy roots store the energy that drives everything above them. From the crown rise long, arching, grass-like leaves, narrow and ribbed, and between them shoot tall, smooth flower stalks that lift the blooms clear of the foliage through summer. On the common orange fulva the flowers open rusty orange and unscented, six tepals flaring from a slender throat, and the plant pushes outward fast on creeping rhizomes. Named hybrids hold a neater clump and paint those same wide blooms in nearly every color but true blue, and the flowers and buds carry a sweet, mild taste.
One fact about this plant overrides its looks entirely. Daylilies are deadly to cats, and even a small taste of leaf, flower, or that loose orange pollen can shut down a cat's kidneys. A home with a cat demands a hard look before planting, and a cut daylily, pollen and all, has no place indoors.
Care
The short version: full sun and average well-drained soil, a moderate drink through the season, and a clump divided every few years to keep those wide blooms coming.
Light
The blades and blooms come into their own in full sun, ideally 6 or more hours a day, where the foliage stays compact and the flowers open full. In partial shade the leaves stretch long and floppy and far fewer scapes rise.
Water
A moderate, even drink through the growing season keeps the fleshy roots plump, watering every 7 to 14 days once established. The plant rides out a dry spell better than most perennials, its leaves merely thinning, yet steady moisture is what swells the heaviest flush of wide flowers.
Soil
Almost any well-drained loam suits the thick roots, and worked-in organic matter feeds them. The plant runs best at a pH of 6.0 to 7.0, though it still anchors into poor, dense, heavy clay ground that would defeat finer-rooted plants.
Humidity
Ordinary outdoor humidity sits fine against the foliage, so there is no figure to chase. Open air moving through the arching blades does more good, since the rots that scar daylilies set into warm, stagnant damp around the crown.
Feeding
The plant is a light feeder, its thick roots needing little. A single dose of balanced general-purpose fertilizer in spring carries most clumps, foliage and scapes alike, through the season.
Pruning
Daily deadheading snaps off the limp, spent flowers and keeps the clump clean-looking, and the bare flower scapes get cut to the base once bloom is done. The long blades, browned and collapsed, are trimmed away in late fall or early spring before new green pushes up.
Size & spacing
The leaf-and-scape mound rises 2.5 to 6 feet (76 to 183 cm) tall by variety and spreads into a clump 24 to 30 inches (61 to 76 cm) wide. Set each one with space around it so air slips freely between the blades and around the crown.
When to plant
A hardy perennial across zones 3 through 9, the daylily dies back to its crown and pushes fresh green blades up again each year. New plants go out in spring or early fall once hard frost has passed, and the scapes raise their fullest flush of bloom 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 rank among the most trouble-free perennials, and what does go wrong tends to mark the leaves or crown rather than kill the plant. The notes below tie what you see, a tunneled blade or a softened crown, to its cause so a minor blemish does not run through the clump.
The crown softens and collapses in warm, humid weather
Southern blight takes hold in hot, muggy spells, rotting the crown to mush and spinning a white, cottony web of threads over the soil studded with tan, seed-sized sclerotia. An infected plant cannot be saved. It is dug out with the soil clinging to it, the drainage is opened up, and mulch is raked back off the crown so the rot does not return.
Fix:
- Remove and destroy infected plants and surrounding soil
- Improve drainage and air circulation
- Avoid burying the crown too deeply
Older clumps knot up tight and raise fewer scapes
Creeping rhizomes drive the clump outward, and after a few seasons the fans knot so tightly that the center thins to bare crown and fewer flower scapes rise. The fix is division. The clump is lifted in early spring or right after bloom, teased apart into individual fans, and replanted with each crown sitting level with the soil.
Fix:
- Dig and divide the clump in early spring or after bloom
- Replant divisions with the crown at soil level
Pale winding tunnels etched the length of the blades
Those squiggling pale lines are the daylily leafminer, whose larvae chew through the inside of the leaf and leave winding mines etched into the green. Held against the light, a blade shows the tunnels as clear, sap-colored tracks. The marks look worse than they are and never kill an established clump, so the heavily mined blades get stripped away and the plant grows on.
Fix:
- Remove and destroy heavily mined leaves
- Maintain plant vigor with adequate water and division
Toxicity
Read this closely if a cat lives with you. Daylilies are deadly to cats, and swallowing any part, even the loose orange pollen groomed off the fur or a sip of vase water, can cause fatal kidney failure within hours. Dogs and horses come through far more mildly, and the wide flowers are edible for people, but for a cat no amount is safe.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Severe
For a cat this is a true emergency. Even a nibble of a blade or petal, a lick of the loose orange pollen off the fur, or a sip of vase water can set off acute kidney failure that turns deadly within hours. The first signs are vomiting, a refusal to eat, and growing lethargy, which slide into full renal shutdown. The cat needs a vet at once, because treatment works only when it starts early.
Dogs Mild
Dogs come through far more lightly than cats. A dog that chews the foliage may drool or have a brief bout of vomiting or loose stools, but it does not face the kidney danger that makes daylilies so deadly to cats.
Horses Mild
In horses, grazing the long blades usually causes no more than a mild stomach upset, with a little drooling or loose manure after a large mouthful.
Rabbits Caution
How daylilies affect rabbits is not well documented, so the plant counts as off limits, with no nibbling of blades or flowers allowed.
Livestock Caution
Firm data on grazing animals is scarce, so cattle, goats, and sheep are kept clear of daylily stands as a sensible precaution against an untested plant.
Birds Caution
The effect on pet and backyard birds is unstudied, so cut blades and loose pollen are kept out of reach until more is known.
People Flowers edible
For people the wide flowers and plump buds are edible, sweet and mild, long used in cooking, so they are safe to eat in moderation. That safety never reaches 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
Registered daylily hybrids run into the tens of thousands, a vast spread of color and form, yet a few species and old favorites show the range best. These are the ones to look at first.
Hemerocallis fulva (Orange / Tawny daylily, 'Ditch lily')
This vigorous species runs outward on rhizomes and opens rusty-orange unscented flowers, six tepals flaring from the throat, and it has naturalized so widely along North American roadsides that it earned the name ditch lily.
Hemerocallis fulva 'Kwanso'
Its double flower is crowded with extra petals layered tight and carries no working stamens, so it sets no seed and creeps outward only on its rhizomes.
Hemerocallis lilioasphodelus (lemon daylily)
This early bloomer lifts fragrant flowers in clear, bright yellow, a sharp visual break from the rusty unscented orange of the common fulva.
Hemerocallis 'Stella de Oro'
This compact, small-statured hybrid reblooms all season, sending up scape after scape of rounded golden-yellow flowers.
How to propagate
Daylilies multiply readily, the fleshy roots and creeping rhizomes pulling apart by hand, and division is the only method most gardeners need to fill a 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.
Division is how the clump becomes many, the work done in early spring as the first green blades push up or in fall once the flowers fade. The clump is dug whole, the tangle of fleshy roots and fans pulled apart so each piece keeps roots and a crown, and the divisions set back at the depth they grew. Driven by fast-creeping rhizomes, they usually root in within a single season and often raise fresh scapes the next year.
Myths
Daylilies are true lilies, so they pose the same danger to cats as any other lily.
The wide, flat daylily flower looks the part, but daylilies belong to Hemerocallis and sit outside Lilium, the true lily genus, so the botany is genuinely different. The danger is the same. 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 wide tepals and plump buds are edible for people, sweet and mild, and have flavored cooking for centuries. That says nothing about cats, for whom even a small exposure can be fatal.