Black Walnut

Juglans nigra

Juglandaceae · broadleaf deciduous tree · native

Last updated

Data Maturity Structured

This profile synthesizes data from multiple published sources. Expert field review is in progress.

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 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂. Black Walnut has reached 'leaf emergence' (1526 GDD₃₂) and is approaching 'flower buds visible', predicted around Apr 30.

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 23, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 1,593 'Leaf emergence' 'Flower buds visible' 78
Seattle / UW 1,554 'Leaf emergence' 'Flower buds visible' 117
Kent / Auburn 1,537 'Leaf emergence' 'Flower buds visible' 134
Olympia / Tumwater 1,505 'Bud break' 'Leaf emergence' 22
Bellingham / Whatcom 1,483 'Bud break' 'Leaf emergence' 43
Tacoma / Puyallup 1,472 'Bud break' 'Leaf emergence' 54
Sequim / Rain Shadow 1,434 'Bud break' 'Leaf emergence' 92
Stage GDD32 Typical Window
'Bud break' BBCH '07' 1410 ''
● 'Leaf emergence' BBCH '11' NOW 1526 ''
○ 'Flower buds visible' BBCH '51' NEXT 1671 '' est. Apr 30 (forecast)

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 23, 2026. Predicted dates use 16-day weather forecast through May 10, 2026, then climate normals.

Diseases (7)

Pests (9)