How-to Guide
How to Grow Daylilies
The short answer
Daylilies (Hemerocallis) grow in USDA zones 3-9 in full sun to partial shade and well-drained soil high in organic matter, and NC State Extension rates their maintenance as low. Each trumpet-shaped bloom lasts only a day, but modern cultivars flower from spring through summer, some until frost. They tolerate occasionally dry soil and are highly salt-tolerant.
The main job is division: Iowa State University Extension says daylilies can be divided in early spring as new growth emerges or in late summer, cutting foliage back to 6-8 inches, splitting the clump into sections with 2 or 3 fans each, and replanting with the crown about 1 inch below the soil surface. Expect divided plants to bloom lightly for the first 1-2 years.
Site, soil, and water
Plant daylilies in full sun to partial shade in well-drained soil high in organic matter. Clumps typically reach 1 to 1.5 feet tall and wide, and established plants tolerate occasionally dry conditions. NC State Extension notes they are highly salt-tolerant, which makes them useful near roads and coasts.
When planting, cover the tuberous roots with about 1 inch of soil. No winter protection or lifting is needed within their hardiness range.
Bloom and deadheading
Each flower opens for a single day, with buds opening in succession along the scape. Snapping off spent blooms keeps plants tidy, and once a scape has finished all its buds it can be cut at the base. With reblooming cultivars, flowering can run from spring through summer to frost.
✔ If an established clump has stopped blooming well, crowding is the usual cause — Colorado State PlantTalk notes daylilies simply need rejuvenating division every three to five years.
Dividing daylilies
- 1Pick the season — Iowa State Extension: divide in early spring as new growth begins to emerge, or in late summer after bloom.
- 2Cut back and dig — For late-summer division, cut foliage back to 6-8 inches first. Dig the entire clump and shake or wash off soil.
- 3Split the clump — Pull the clump apart, using a sharp knife on large dense clumps. Keep 2 or 3 fans of leaves and a good root system per division.
- 4Replant promptly — Set each division with the crown about 1 inch below the soil surface and water thoroughly. Divisions usually bloom sparsely for 1-2 years before hitting full stride.
Common problems
- NC State Extension reports no serious pest or disease problems, with Southern blight an occasional issue in warm, wet conditions.
- Declining bloom in older plantings usually signals an overcrowded clump that needs division.
⚠ NC State Extension warns daylilies are toxic to cats — ingestion can cause vomiting, lethargy, kidney failure, and even death (dogs are unaffected). If a cat has eaten any part, check ASPCA poison-control guidance and call a veterinarian immediately.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- North Carolina Extension Gardener Plant Toolbox — Hemerocallis (Daylily) — Zones 3-9; full sun to part shade in well-drained organic soil; plant tubers under 1 inch of soil; blooms last one day, cultivars flower spring to frost; divide fall or spring; salt tolerant; toxic to cats
- Iowa State University Extension — When can I divide daylilies? — Divide in early spring or late summer; cut foliage to 6-8 inches; keep 2-3 fans per division; replant crown 1 inch deep; sparse bloom for 1-2 years after division
- Colorado State University PlantTalk — Dividing perennials — Daylilies need rejuvenating division every three to five years and are best divided a few weeks after flowering