Green Hawthorn
'Full bloom'Crataegus viridis
Rosaceae · broadleaf deciduous tree · native
Last updated
Quick Facts
Height
20–40 ft
Spread
20-35 ft
Growth Rate
Slow
Light
Full Sun
Soil
Well Drained, Adaptable
Water
Low to moderate
Hardiness
Zone Zones 4a–8b
Bloom Time
May
Fall Color
Purple, scarlet
Origin
from Maryland, Virginia to Illinois
Watch for this season
Fire BlightHigh
Bloom Infection Window
RustHigh
Aecial Stage (Alternate Host)
Scale insectHigh
Crawler Emergence
Tent caterpillarHigh
Larval Feeding
+ 3 more — see full disease and pest lists below
Phenological Calendar
As of May 14, 2026, Puget Sound stations range from 1926.1 to 2121.1 GDD₃₂. Green Hawthorn has passed 'full bloom' (1370 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 14, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,121 | 'Full bloom' | — | — |
| Kent / Auburn | 2,113 | 'Full bloom' | — | — |
| Seattle / UW | 2,085 | 'Full bloom' | — | — |
| Olympia / Tumwater | 2,047 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 2,016 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 1,994 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 1,926 | 'Full bloom' | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 1200 | '' |
| ● 'Full bloom' BBCH '65' NOW | 1370 | '' |
Range: 888–1070 GDD₃₂
(6yr)
Source: 'Master catalog (OSU, UMD), converted GDD50->GDD32 via Kent bloom-date mapping' About GDD₃₂ →
Season tracker for Kent / Auburn as of May 14, 2026. Predicted dates use 16-day weather forecast through May 30, 2026, then climate normals.
Diseases: Regionally Documented (6)
Venturia spp. — multiple host-specific species: V Scab Multiple genera (Melampsoridium, Thekopsora, Naohidemyces... Rust Symptom category — not a single disease Leaf Spot Erwinia amylovora Fire Blight Symptom category — not a single disease Canker Multiple obligate biotrophic fungi (Erysiphales: Erysipha... Powdery Mildew
Pests: Regionally Documented (10)
Tetranychidae Spider mite Coccoidea Scale insect Caliroa cerasi Pear slug Dysaphis crataegi Hawthorn aphid Choreutis pariana Apple-and-thorn skeletonizer Acanthococcus azaleae Azalea bark scale Enarmonia formosana Cherry bark tortrix Hyphantria cunea Fall webworm Tortricidae Leafroller Malacosoma spp. Tent caterpillar
Cultivars (1)
'Winter King'
Common name: Winter King Hawthorn Winter King Green Hawthorn; Mature height: 20–25 ft
Hardy to USDA Zone 4
Data Maturity Structured Multiple sources. Expert review underway.