Common names of flowers are colorful, but they mislead. One gardener’s trout lily is another’s dogtooth violet, and plants called lilies range across several botanical families. The two most confusing are true lilies (Lilium) and daylilies (Hemerocallis), which look similar in photos but differ in roots, stems, leaves, and bloom habits.
Latin names settle the argument. True lilies belong to the genus Lilium and grow from bulbs, while daylilies belong to Hemerocallis and grow from tuberous roots. Gardeners who like the look also grow plants such as alstroemeria, sold as Peruvian lilies, and the routine for growing and caring for Peruvian lilies shows how different the care can be from one lily lookalike to the next.
What Is a True Lily?
A true lily is any plant in the genus Lilium, a group of about 100 species native mostly to the Northern Hemisphere. Every true lily grows from a scaly bulb, produces a single stem, and carries its flowers at the top of that stem. Easter lilies, Asiatic lilies, Oriental lilies, and tiger lilies are all true lilies.
Gardeners rarely buy a true lily by species name alone. The hybrids sold at garden centers group into divisions: Asiatic lilies bloom early with upright, mostly unscented flowers; Oriental lilies bloom later with large, fragrant blooms; trumpet and Aurelian types carry long funnels; and species lilies stay closest to their wild forms. All of them share the bulb, the single stem, and the six-petal flower that define the genus.
Why Botanical Names Matter
The genus name removes the guesswork. When a plant tag says Lilium, the plant is a true lily with a bulb and the care that goes with it. When the tag says Hemerocallis, it is a daylily. The same habit protects gardeners elsewhere in the plant world, where lookalikes share common names but need different conditions.
Plants That Borrow the Lily Name
Calla lilies grow from rhizomes, peace lilies are aroids, and canna lilies are tropical rhizome plants, none of them related to Lilium. Knowing which family a plant belongs to decides everything from winter care to how deep to plant it.
Daylily vs. Lily: Key Differences at a Glance
Comparing the two plants side by side makes the distinctions obvious. The table below summarizes the main differences between a daylily and a true lily.
| Feature | True lily (Lilium) | Daylily (Hemerocallis) |
|---|---|---|
| How it grows | Bulb | Tuberous roots |
| Stems | Single stem | Multiple stems |
| Petals | 6 petals, not layered | 6 petals, layered |
| Anthers | 6 anthers plus 6 stamens | 2 anthers plus 6 to 7 stamens |
| Leaves | Spiral of leaves up the stem | Long, flat strap blades at soil level |
| Bloom time | A week or more per flower | One day per flower |
| Flower shapes | Trumpet, bowl, funnel, recurved | Circular, triangular, double, ruffled, star, spider |
What the Comparison Shows
Every row of the table traces back to the same underlying difference: a true lily is a bulb plant built around one flowering stem, while a daylily is a clumping perennial that spreads from roots and reblooms from new buds. Check the leaves and the anthers first, since those two features are visible without digging.
Other plants muddy the naming even further. Cannas are often planted alongside lilies in summer borders, and because they are tender rhizomes in most climates, the fall digging routine for overwintering canna lilies differs completely from the care either true lilies or daylilies need.
Roots and Growth Habits: Bulbs vs. Tuberous Roots
Dig down and the difference appears immediately. A true lily bulb is a cluster of fleshy scales that stores the plant’s energy for the next season. A daylily spreads from a dense network of tuberous roots that hold moisture and nutrients.
How Each Plant Spreads
Daylilies multiply by division: the root clump grows outward and can be split into new plants every few years. True lilies multiply more slowly, by offsets around the parent bulb and by stem bulbils on some species. A daylily clump doubles in size within a couple of seasons, while a lily clump expands at a more measured pace.
Planting Depth and Handling
Plant true lily bulbs about three times their height, pointed end up, in soil that drains well. Set daylily divisions so the crown sits just below the surface. Lily bulbs dry out quickly and need planting soon after purchase; daylily roots tolerate being out of the ground for a day or two.
- Dig a hole three times the bulb height, loosening the soil at the base.
- Set the bulb pointed end up and spread the roots outward.
- Backfill and water in, then mark the spot so fall cleanup does not disturb it.
- Mulch over the root zone to keep it cool through summer.
Divide daylilies every three to five years in early spring or late summer. Lift the whole clump with a fork, shake off the soil, and pull the fans apart by hand or cut through the crown with a knife. Each division needs at least two or three fans to bloom the following season, and the replanted pieces settle in quickly because the tuberous roots carry their own water supply.
Leaves and Stems: The Fastest Way to Tell Them Apart
The foliage is the giveaway. Daylilies produce long, flat, strap-shaped blades that arch out from the soil line in a fountain, while true lilies carry leaves arranged in a spiral up a single central stem.
Reading the Foliage
A clump of arching grass-like blades with no visible stem belongs to a daylily. A plant with leaves attached all the way up a stalk, so the flowers appear to rise out of a leafy tower, is a true lily. This works even when no flowers are showing, which makes it the most reliable field test.
What the Stems Tell You
True lilies grow one stem per bulb, so a single stalk usually means one bulb underneath. Daylilies push up many stems from one crown, and each stem carries several buds that open in sequence. The multi-stem habit is why a mature daylily clump looks full even in its first year.
Winter behavior follows the same pattern. True lilies die back to the bulb and tolerate cold soil well, with many species hardy to zone 4 or colder. Daylilies also go dormant, but their evergreen and semi-evergreen cultivars keep some foliage through mild winters, which is why a daylily bed still shows structure in December while a lily border is bare ground.
Flowers: Petals, Anthers, and Bloom Time
The blooms reveal the same story. Both plants produce six-petal flowers, but true lily petals are not layered and the flowers last a week or more. A daylily blossom opens for a single day, then fades, while new buds on the same stem keep the show going for weeks.
Counting Petals and Stamens
Count the anthers and the two plants separate cleanly. True lilies carry six anthers and six stamens, while daylilies carry two anthers with six to seven stamens. The six-petal rule holds for both, so the anther count is the reliable number.
Shapes and Colors
True lilies flower in trumpet, bowl, funnel, and recurved forms, with petals that curl back hard on Turk’s cap types. Daylilies add circular, triangular, double, ruffled, star, and spider shapes, and modern hybrids come in nearly every color except true blue. Both ranges give gardeners plenty of choice.
Scent separates them at close range. Many Oriental and trumpet lilies perfume an entire garden corner in the evening, while daylilies are mostly unscented, with a few exceptions among the nocturnal tetraploid hybrids. Bees and hummingbirds work both plants, and the long bloom sequence of a daylily clump keeps nectar flowing even though each individual flower lasts a day.
Growing Conditions and Choosing the Right Plant
The two plants ask for different things in the garden. True lilies want full sun to light shade, cool root zones, and well-drained soil; daylilies tolerate more heat, poorer soil, and drier spells once established.
Sun, Soil, and Water Needs
Give true lilies six or more hours of sun, mulch over the roots to keep them cool, and avoid heavy clay. Daylilies handle the same sun but shrug off summer drought and are among the easiest perennials for new gardeners. Neither plant is fussy about pH, though lilies prefer slightly acidic ground.
Which Is Right for Your Garden
- Daylilies for low-maintenance borders, slopes, and roadside plantings
- True lilies for cut flowers and formal beds where the bloom is the centerpiece
- Daylilies where deer pressure is high, since they are less favored
- True lilies where you can stake taller stems and protect them from wind
Combining the two in one border works well when the heights line up. Plant daylilies in the front third for foliage mass, set true lilies behind them so the tall stems rise through the clumps, and choose a lily that blooms after the daylilies peak to extend the color. The staggered root systems, bulbs in one case and spreading roots in the other, do not compete for the same soil space.
Both plants are toxic to cats, so keep either type out of reach of indoor pets. Choose daylilies when you want a carefree clump that multiplies, and true lilies when you want tall, fragrant stems for the vase, then plant accordingly and the confusion ends at the garden center.