Honeylocust
Gleditsia triacanthos
Fabaceae · broadleaf deciduous tree · native
Last updated
You recognize Honeylocust by its feathery bipinnate leaves creating dappled shade, and its spiney trunk and branches that inspired the common name. The fragrant yellowish flowers appear before leaves in spring, followed by long brown pods. This fast-growing native prefers infrequent deep watering and adapts to poor soils.
Honeylocust tolerates full sun and a wide range of soil conditions, from clay to sand. Plant thornless cultivars where spines are problematic. Once established, it requires minimal watering even in drought. Monitor for stem borers and webworms. The tree's rapid growth and low maintenance make it valuable for difficult sites, though falling pods and leaflets require occasional cleanup.
Quick Facts
Phenological Calendar
As of April 3, 2026, Puget Sound stations range from 1070 to 1180.6 GDD₃₂. Honeylocust typically reaches bloom start at 1794 GDD₃₂, predicted around May 7.
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 | Bloom start | 613 |
| Seattle / UW | 1,171 | Pre-season | Bloom start | 623 |
| Kent / Auburn | 1,111 | Pre-season | Bloom start | 683 |
| Olympia / Tumwater | 1,106 | Pre-season | Bloom start | 688 |
| Bellingham / Whatcom | 1,101 | Pre-season | Bloom start | 693 |
| Tacoma / Puyallup | 1,075 | Pre-season | Bloom start | 719 |
| Sequim / Rain Shadow | 1,070 | Pre-season | Bloom start | 724 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ Bloom start BBCH 61 NEXT | 1794 | May 1-May 31 est. May 7 (avg) |
| Full bloom BBCH 65 | 2269 | — est. May 27 (avg) |
| Bud break BBCH 07 | — | Feb 15-Mar 15 |
| Leaf emergence BBCH 11 | — | Mar 1-Apr 1 |
| Bloom end / petal fall BBCH 69 | — | May 15-Jun 15 |
| Fruit/seed development BBCH 71 | — | Jun 1-Aug 31 |
| Fruit/seed maturity BBCH 85 | — | Sep 1-Nov 30 |
| Fall color / leaf senescence BBCH 93 | — | Oct 1-Nov 15 |
| Dormancy BBCH 97 | — | Nov 15-Feb 28 |
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 Apr 3, 2026. Predicted dates use 16-day weather forecast through Apr 19, 2026, then climate normals.