Plant daylilies (Hemerocallis) in early fall or early spring, which Clemson calls the best times, though they tolerate planting almost any time. UMN plants as soon as the soil can be worked in spring. Set the crown no more than 1 inch deep, space plants 18 to 24 inches apart (Clemson), and give them at least 6 hours of sun (UMN). Divide crowded clumps right after flowering or in early spring.
Daylilies are not true lilies. They grow from tuberous roots, not bulbs, and the name comes from the Greek for day and beauty, because each flower lasts only a day (NC State). A clump blooms for 30 to 40 days somewhere between late spring and fall, depending on the cultivar (Clemson). There are over 35,000 registered cultivars (UMN), ranging from 8 inches to 5 feet tall with flowers 2 to 8 inches across (Clemson). NC State lists them as hardy in zones 3a to 9b. For true lilies, see when to plant lilies.
When to plant daylilies
| Timing | What the sources say |
|---|---|
| Early fall | Clemson calls early fall and early spring the best times to plant, and says South Carolina gardeners should avoid summer heat |
| Early spring, as soon as the soil can be worked | UMN plants then; Clemson also names early spring |
| Any time in the growing season (potted plants) | Clemson says daylilies tolerate planting at almost any time; water weekly until established |
| Right after flowering (dividing) | Clemson usually divides then, though it says division is tolerated all season; UMN divides in early spring or just after bloom; NC State says fall or spring |
| Every 3 to 5 years (how often to divide) | UMN divides crowded clumps on this schedule; Clemson says plants mature in 3 to 4 years |
Use our planting calendar to see your frost dates. Our reading is that fall planting suits hot-summer areas like South Carolina, and early spring suits cold areas like Minnesota, where fall-planted roots have less time to settle before the ground freezes. On first-year bloom, Clemson says new plants may flower the year they're planted, while UMN says spring divisions may skip flowering that summer.
How to plant daylilies
| What the sources say | |
|---|---|
| Light | At least 6 hours of sun (UMN); full sun to part shade (NC State). Clemson gives dark red and purple cultivars afternoon shade so they don't fade |
| Soil | Well drained with organic matter, pH 6 to 6.5; use raised beds if drainage is poor (Clemson). UMN works in compost and keeps them out from under trees and shrubs |
| Depth | Crown no deeper than 1 inch (Clemson, UMN). Clemson says planting too deep reduces flowering and causes decline |
| Spacing | 18 to 24 inches (Clemson) |
| Height | 8 in to 5 ft (Clemson); 1 to 3 ft for most garden types (NC State). NC State's own page also says 1 to 1.5 ft, so check the cultivar tag |
| Foliage type | Clemson says evergreen types do best in hot, mild-winter areas, and dormant types prefer cold winters |
Rebloomers such as 'Stella de Oro' and 'Happy Returns' flower more than once (Clemson). UMN says rebloomers haven't performed well in Minnesota's short season, so it recommends choosing cultivars proven in your region.
Watering, feeding and deadheading
- Water weekly until established (Clemson). UMN aims for 1 inch of water a week.
- Feed lightly. Clemson uses a slow-release fertilizer in early spring and again in midsummer, and recommends a soil test first.
- Deadhead. Remove spent flowers and seed pods, and cut bare flower stalks (scapes) to the ground (Clemson). UMN says letting plants set seed reduces the next year's flowers.
- Divide crowded clumps into sections of 2 or 3 fans, and cut the leaves back to 5 or 6 inches (UMN).
- Mind the orange one. Orange daylily (H. fulva) is an Asian species that has escaped across North America and spreads fast by rhizomes (NC State). For a tidy bed, our reading is to choose clump-forming hybrids instead.
Daylilies in containers
NC State lists containers as a use, and Clemson says small cultivars can be planted in containers, such as the 18-inch rebloomer 'Happy Returns'. Use a free-draining mix and water more often than in the ground (GardenPal reasoning).
Fall and winter
- No lifting needed. NC State says the roots stay in the ground over winter.
- Clean up dead leaves. Clemson removes dead foliage around the base in fall, because the leaf streak fungus overwinters on it.
- Mulch new plants. UMN covers plants that aren't established with straw or shredded leaves for winter.
Pests and problems
Clemson says pests and diseases are usually minor with good care. It lists leaf streak (yellow streaks along the leaf center), daylily rust (orange spores under the leaves, so check the undersides before you buy), root-knot nematodes in sandy soil, and bacterial soft rot in wet, poorly drained spots. Insects include thrips, spider mites, aphids and the daylily leafminer, plus slugs and snails (Clemson). UMN mentions aphids and thrips on the buds. Clemson's prevention list is to buy clean plants, plant at the right depth, give them air and drainage, and water at the soil rather than overhead. NC State notes that deer often browse daylilies.
Daylilies around the vegetable garden
Daylilies give nectar to butterflies and hummingbirds (NC State) and tolerate salt (NC State), and their dense roots hold banks and slopes (NC State, Clemson). Chicago Botanic Garden pairs bee balm with daylilies, and our other guides pair them with coral bells, lavender and alliums. For another summer perennial, see when to plant bee balm. If you have cats, our reading is to keep daylilies out of beds they patrol. For another summer border perennial, see when to plant phlox.
Frequently asked questions
When is the best time to plant daylilies?
Early fall or early spring (Clemson). UMN plants in spring as soon as the soil can be worked.
Can I plant daylilies in summer?
Yes. Clemson says daylilies tolerate planting at almost any time, but in hot climates it recommends fall or spring. Water weekly until they are established.
How deep should I plant daylilies?
With the crown no more than 1 inch below the soil (Clemson, UMN). Planting deeper reduces flowering (Clemson).
When should I divide daylilies?
Right after flowering or in early spring, every 3 to 5 years (UMN). Clemson says division is tolerated all season.
Are daylilies poisonous to cats?
Yes. NC State and the FDA say daylilies can be toxic to cats. Call a veterinarian right away if a cat may have been exposed.
Are daylilies the same as lilies?
No. Daylilies (<i>Hemerocallis</i>) grow from tuberous roots, not bulbs, and each flower lasts only a day (NC State).
Enter your frost dates to plan fall or spring daylily planting.
Open itSources
- Virginia Cooperative Extension, "Companion Planting in Gardening" (SPES-620P)
- University of Maryland Extension, "Vegetable Succession and Companion Planting"
- Oregon State University Extension, "Companion Planting"
- Penn State Extension, "Herbs Make Good Plant Partners and Companions"
- University of Minnesota Extension, "Planting the vegetable garden"
- USDA Plant Hardiness Zone Map
- NOAA NCEI U.S. Climate Normals (frost/freeze data)
- Clemson Cooperative Extension HGIC, "Daylily"
- Clemson Cooperative Extension HGIC, "Daylily Diseases and Insect Pests"
- NC State Extension Gardener Plant Toolbox, "Hemerocallis"
- NC State Extension Gardener Plant Toolbox, "Hemerocallis fulva"
- University of Minnesota Extension, "Daylilies"
- U.S. FDA, "Lovely lilies and curious cats: a dangerous combination"
Pairings are summarized in our own words from extension-service guidance. Research support for many companion effects is limited, so treat them as good habits, not guarantees.