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Japanese Pagodatree Scholar-tree

Styphnolobium japonicum

Fabaceae · broadleaf deciduous tree · introduced

Last updated

Data Coverage 4 of 6 dimensions
Site Data
Threats
Cultivars
Phenology
GDD Thresholds
Puget Sound

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

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Mar 22, 2026
Station GDD₃₂ Current Stage Next To Go
Seattle / UW 1,013 Pre-season Beginning of flowering 4,898
Issaquah / East King 1,006 Pre-season Beginning of flowering 4,905
Olympia / Tumwater 952 Pre-season Beginning of flowering 4,959
Bellingham / Whatcom 948 Pre-season Beginning of flowering 4,963
Kent / Auburn 942 Pre-season Beginning of flowering 4,969
Sequim / Rain Shadow 924 Pre-season Beginning of flowering 4,987
Tacoma / Puyallup 921 Pre-season Beginning of flowering 4,990
Stage GDD32 Typical Window
Beginning of flowering BBCH 61 NEXT 5911 est. Sep 24 (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 Mar 22, 2026. Predicted dates use 16-day weather forecast through Apr 7, 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