Red Buckeye
Aesculus pavia
Sapindaceae, Hippocastanaceae · broadleaf deciduous shrub · native
Last updated
Data Maturity Structured
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Quick Facts
Height
10-20 ft
Spread
9 ft
Growth Rate
Fast
Light
Full Sun to Shade
Soil
Moist
Water
Moderate
Hardiness
Zone Zones 5a–8b
Bloom Time
April to May
Origin
extends from Virginia to Florida and east to Louisiana and
Phenological Calendar
As of April 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂. Red Buckeye has passed 'full bloom' (1229 GDD₃₂).
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 | 'Full bloom' | — | — |
| Seattle / UW | 1,554 | 'Full bloom' | — | — |
| Kent / Auburn | 1,537 | 'Full bloom' | — | — |
| Olympia / Tumwater | 1,505 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 1,483 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 1,472 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 1,434 | 'Full bloom' | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 973 | '' |
| ● 'Full bloom' BBCH '65' NOW | 1229 | '' |
Range: 728–874 GDD₃₂
(6yr)
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Source GDD₅₀ thresholds from Herms 2004 (OSU, Secrest Arboretum, Ohio) and UMD IPMnet (Gill & Klick, mid-Atlantic), converted to GDD₃₂ via Kent bloom-date mapping. Season tracker for Kent / Auburn as of Apr 23, 2026. Predicted dates use 16-day weather forecast through May 10, 2026, then climate normals.
Diseases (3)
Cultivars (1)
'Humilis'
Common name: Dwarf Red Buckeye; Mature height: 15 ft