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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 3, 2026, Puget Sound stations range from 1070 to 1180.6 GDD₃₂. Black Walnut typically reaches 'bud break' at 1410 GDD₃₂, predicted around Apr 18.

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 3, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 1,181 Pre-season 'Bud break' 229
Seattle / UW 1,171 Pre-season 'Bud break' 239
Kent / Auburn 1,111 Pre-season 'Bud break' 299
Olympia / Tumwater 1,106 Pre-season 'Bud break' 304
Bellingham / Whatcom 1,101 Pre-season 'Bud break' 309
Tacoma / Puyallup 1,075 Pre-season 'Bud break' 335
Sequim / Rain Shadow 1,070 Pre-season 'Bud break' 340
Stage GDD32 Typical Window
○ 'Bud break' BBCH '07' NEXT 1410 '' est. Apr 18 (forecast)
'Leaf emergence' BBCH '11' 1526 '' est. Apr 24 (avg)
'Flower buds visible' BBCH '51' 1671 '' est. May 2 (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 3, 2026. Predicted dates use 16-day weather forecast through Apr 19, 2026, then climate normals.

Diseases (7)

Pests (10)