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Black Walnut

Juglans nigra

Juglandaceae · broadleaf deciduous tree · native

Last updated

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

Quick Facts

Height
100 ft
Spread
65 ft
Growth Rate
Fast
Light
Full Sun
Soil
Well Drained
Water
High
Hardiness
Zone Zones 4a–8b
Bloom Time
May to June
Origin
Massachusetts to Florida, west to Minnesota and Texas

Phenological Calendar

As of April 12, 2026, Puget Sound stations range from 1235.8 to 1375.3 GDD₃₂. Black Walnut typically reaches 'bud break' at 1410 GDD₃₂, predicted around Apr 19.

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 'Bud break' 35
Seattle / UW 1,348 Pre-season 'Bud break' 62
Kent / Auburn 1,308 Pre-season 'Bud break' 102
Olympia / Tumwater 1,292 Pre-season 'Bud break' 118
Bellingham / Whatcom 1,270 Pre-season 'Bud break' 140
Tacoma / Puyallup 1,258 Pre-season 'Bud break' 152
Sequim / Rain Shadow 1,236 Pre-season 'Bud break' 174
Stage GDD32 Typical Window
○ 'Bud break' BBCH '07' NEXT 1410 '' est. Apr 19 (forecast)
'Leaf emergence' BBCH '11' 1526 '' est. Apr 25 (forecast)
'Flower buds visible' BBCH '51' 1671 '' est. May 1 (avg)

GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? GDD₃₂ thresholds from USA National Phenology Network citizen science observations (WA+OR). Season tracker for Kent / Auburn as of Apr 12, 2026. Predicted dates use 16-day weather forecast through Apr 28, 2026, then climate normals.

Diseases (7)

Pests (10)