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 19, 2026, Puget Sound stations range from 1342.9 to 1500.8 GDD₃₂. Japanese Pagodatree Scholar-tree typically reaches 'first bloom' at 4200 GDD₃₂, predicted around Jul 27.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 19, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,501 | Pre-season | 'First bloom' | 2,699 |
| Seattle / UW | 1,465 | Pre-season | 'First bloom' | 2,735 |
| Kent / Auburn | 1,441 | Pre-season | 'First bloom' | 2,759 |
| Olympia / Tumwater | 1,415 | Pre-season | 'First bloom' | 2,785 |
| Bellingham / Whatcom | 1,390 | Pre-season | 'First bloom' | 2,810 |
| Tacoma / Puyallup | 1,381 | Pre-season | 'First bloom' | 2,820 |
| Sequim / Rain Shadow | 1,343 | Pre-season | 'First bloom' | 2,857 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'First bloom' BBCH '61' NEXT | 4200 | '' est. Jul 27 (avg) |
| 'Full bloom' BBCH '65' | 4700 | '' est. Aug 11 (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 19, 2026. Predicted dates use 16-day weather forecast through May 5, 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