American Yellowwood
Cladrastis kentukea
Fabaceae · broadleaf deciduous tree · introduced
Last updated
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
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 | Bloom start | 1,164 |
| Issaquah / East King | 1,006 | Pre-season | Bloom start | 1,171 |
| Olympia / Tumwater | 952 | Pre-season | Bloom start | 1,225 |
| Bellingham / Whatcom | 948 | Pre-season | Bloom start | 1,229 |
| Kent / Auburn | 942 | Pre-season | Bloom start | 1,235 |
| Sequim / Rain Shadow | 924 | Pre-season | Bloom start | 1,253 |
| Tacoma / Puyallup | 921 | Pre-season | Bloom start | 1,256 |
| 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 26 (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 |
| Full bloom BBCH 65 | 2329 | — est. Jun 1 (avg) |
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.