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American Yellowwood

Cladrastis kentukea

Fabaceae · broadleaf deciduous tree · introduced

Last updated

Data Coverage 3 of 6 dimensions
Site Data
Threats
Cultivars
Phenology
GDD Thresholds
Puget Sound

American yellowwood (Cladrastis kentukea, Fabaceae) is a deciduous tree native to the southeastern United States (North Carolina, Tennessee, and surrounding states), where it occurs naturally on limestone cliffs and ridges. It reaches 30 to 50 feet tall with low branching and a broad, rounded crown of delicate branches. Odd-pinnately compound leaves (20 to 30 centimeters, 7 to 9 leaflets) turn yellow-orange in fall. Small, fragrant white flowers hang in pendulous clusters in May to June, followed by brown legume pods.

American yellowwood grows in sun to part shade on well-drained soils across a broad pH range (4.8 to 7.5) with low water needs and drought tolerance once established, hardy in Zones 4a to 8b. Growth is moderate, reaching about 25 feet at 20 years. No pest or disease issues are documented. No cultivars are in the trade. The tree provides nesting sites for songbirds and pollen and nectar for bees and pollinators.

Quick Facts

Height
30–50 ft
Growth Rate
Moderate
Light
Sun to Part Shade
Soil
Well Drained
Water
Low
Hardiness
Zone Zones 4a–8b
Bloom Time
May
Fall Color
Brown
Origin
limestone cliffs and ridges

Phenological Calendar

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Mar 30, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 1,116 Pre-season Bloom start 1,061
Seattle / UW 1,112 Pre-season Bloom start 1,065
Olympia / Tumwater 1,049 Pre-season Bloom start 1,129
Kent / Auburn 1,048 Pre-season Bloom start 1,129
Bellingham / Whatcom 1,041 Pre-season Bloom start 1,136
Tacoma / Puyallup 1,017 Pre-season Bloom start 1,160
Sequim / Rain Shadow 1,012 Pre-season Bloom start 1,165
Stage GDD32 Typical Window
Bud break BBCH 07 Feb 15-Mar 15
Leaf emergence BBCH 11 Mar 1-Apr 1
Bloom start BBCH 61 NEXT 2177 Jun 1-Jun 30 est. May 23 (avg)
Full bloom BBCH 65 2329 est. May 30 (avg)
Bloom end / petal fall BBCH 69 Jun 15-Jul 15
Fruit/seed development BBCH 71 Jun 1-Aug 31
Fall color / leaf senescence BBCH 93 Oct 1-Nov 15
Dormancy BBCH 97 Nov 15-Feb 28
Range: 1621–1894 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 30, 2026. Predicted dates use 16-day weather forecast through Apr 15, 2026, then climate normals.