Red Buckeye
'Full bloom'Aesculus pavia
Sapindaceae, Hippocastanaceae · broadleaf deciduous shrub · introduced
Last updated
Plant Profile
Size & Form
Height
10-20 ft
Spread
9 ft
Growth Rate
Fast
Site Requirements
Light
Full Sun to Shade
Soil Drainage
Moist
Soil pH
4.5-8.5
Water
Moderate
Drought Tolerance
Moderate
Hardiness
Zones 5a–8b
Ornamental Interest
Bloom Time
April to May
Fall Color
Red
Origin
extends from Virginia to Florida and east to Louisiana and
Watch for this season
Powdery MildewHigh
Active Conidial Spread
Diseases: Regionally Documented (2)
Phenological Calendar
As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Red Buckeye has passed 'full bloom' (1229 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,673 | 'Full bloom' | — | — |
| Kent / Auburn | 2,665 | 'Full bloom' | — | — |
| Seattle / UW | 2,610 | 'Full bloom' | — | — |
| Olympia / Tumwater | 2,570 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 2,535 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 2,533 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 2,436 | 'Full bloom' | — | — |
View full calendar (2 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 973 | '' |
| ● 'Full bloom' BBCH '65' NOW | 1229 | '' |
Range: 728–874 GDD₃₂
(6yr)
Source: 'Master catalog (OSU, UMD), converted GDD50->GDD32 via Kent bloom-date mapping' About GDD₃₂ →
Season tracker for Kent / Auburn as of Jun 3, 2026. Predicted dates use 16-day weather forecast through Jun 19, 2026, then climate normals.
Cultivars (1)
'Humilis'
Common name: Dwarf Red Buckeye; Mature height: 15 ft
Data Maturity Structured Multiple sources. Expert review underway.