Daylily
Hemerocallis
Asphodelaceae · perennial · introduced
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Daylily (Hemerocallis, Asphodelaceae) is a genus of perennials, each flower lasting just one day (the genus name derives from the Greek hemera, day, and kallos, beauty). Over 80,000 cultivars have been registered. Bloom periods span spring through frost depending on cultivar selection.
Documented diseases include daylily rust; pest associations include thrips and daylily gall midge. Daylily petals are edible in many cultivars but the plant is toxic to cats (potentially fatal). See Hemerocallis hybrid for cultivar details.
Quick Facts
Phenological Calendar
As of April 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂. Daylily typically reaches 'full bloom' at 3398 GDD₃₂, predicted around Jul 4.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 23, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,593 | Pre-season | 'Full bloom' | 1,805 |
| Seattle / UW | 1,554 | Pre-season | 'Full bloom' | 1,844 |
| Kent / Auburn | 1,537 | Pre-season | 'Full bloom' | 1,861 |
| Olympia / Tumwater | 1,505 | Pre-season | 'Full bloom' | 1,894 |
| Bellingham / Whatcom | 1,483 | Pre-season | 'Full bloom' | 1,915 |
| Tacoma / Puyallup | 1,472 | Pre-season | 'Full bloom' | 1,926 |
| Sequim / Rain Shadow | 1,434 | Pre-season | 'Full bloom' | 1,964 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'Full bloom' BBCH '65' NEXT | 3398 | '' est. Jul 4 (avg) |
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Hover over GDD values for source details. Season tracker for Kent / Auburn as of Apr 23, 2026. Predicted dates use 16-day weather forecast through May 9, 2026, then climate normals.