Japanese Pagodatree Scholar-tree
Styphnolobium japonicum
Fabaceae · broadleaf deciduous tree · introduced
Last updated
Data Coverage 4 of 6 dimensions
Quick Facts
Height
35–50 ft
Light
Part Shade
Hardiness
Zone Zones 4a–8b
Bloom Time
July to August
Origin
China and Korea, but not Japan Invasive: This species has
Phenological Calendar
As of April 12, 2026, Puget Sound stations range from 1235.8 to 1375.3 GDD₃₂. Japanese Pagodatree Scholar-tree typically reaches 'first bloom' at 4200 GDD₃₂, predicted around Jul 29.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 12, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,375 | Pre-season | 'First bloom' | 2,825 |
| Seattle / UW | 1,348 | Pre-season | 'First bloom' | 2,852 |
| Kent / Auburn | 1,308 | Pre-season | 'First bloom' | 2,892 |
| Olympia / Tumwater | 1,292 | Pre-season | 'First bloom' | 2,908 |
| Bellingham / Whatcom | 1,270 | Pre-season | 'First bloom' | 2,930 |
| Tacoma / Puyallup | 1,258 | Pre-season | 'First bloom' | 2,942 |
| Sequim / Rain Shadow | 1,236 | Pre-season | 'First bloom' | 2,964 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'First bloom' BBCH '61' NEXT | 4200 | '' est. Jul 29 (avg) |
| 'Full bloom' BBCH '65' | 4700 | '' est. Aug 13 (avg) |
Range: 3827–4233 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 12, 2026. Predicted dates use 16-day weather forecast through Apr 28, 2026, then climate normals.
Cultivars (2)
'Millstone'
Common name: Millstone Japanese Pagodatree; Mature height: 45 ft
Hardy to USDA Zone 5
'Pendula'
Common name: Weeping Scholar-tree Dragon-claw Tree; Mature height: 15–25 ft
Hardy to USDA Zone 4