Evergreen Blackberry Cutleaf Blackberry
Rubus laciniatus
Rosaceae · vine groundcover · naturalized
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Evergreen blackberry (Rubus laciniatus), also called cutleaf blackberry, is a broadleaf shrub in the Rosaceae family originating from Eurasia, now widely naturalized in North America. It reaches 10 ft tall (12 ft at 20 years) with an erect, thicket-forming habit and fast growth. Pink to white flowers appear in large terminal prickly panicles. The distinctive deeply cut (laciniate) leaves are semi-evergreen.
Evergreen blackberry is hardy in zones 5a-8b and prefers part shade with wet-tolerant drainage (pH 5.2-7.7) and moderate water, tolerating anaerobic soil with a minimum 12-inch root depth. Thirty-two diseases and 4 pests are documented. It is classified as a Washington State Class C Noxious Weed with low drought tolerance.
Quick Facts
Phenological Calendar
As of April 24, 2026, Puget Sound stations range from 1455.1 to 1613.4 GDD₃₂. Evergreen Blackberry Cutleaf Blackberry has reached 'bud break' (844 GDD₃₂) and is approaching 'first bloom', predicted around Jun 16.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 24, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,613 | 'Bud break' | 'First bloom' | 1,250 |
| Seattle / UW | 1,574 | 'Bud break' | 'First bloom' | 1,289 |
| Kent / Auburn | 1,559 | 'Bud break' | 'First bloom' | 1,304 |
| Olympia / Tumwater | 1,524 | 'Bud break' | 'First bloom' | 1,340 |
| Bellingham / Whatcom | 1,504 | 'Bud break' | 'First bloom' | 1,359 |
| Tacoma / Puyallup | 1,492 | 'Bud break' | 'First bloom' | 1,371 |
| Sequim / Rain Shadow | 1,455 | 'Bud break' | 'First bloom' | 1,408 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ● 'Bud break' BBCH '07' NOW | 844 | '' |
| ○ 'First bloom' BBCH '61' NEXT | 2863 | '' est. Jun 16 (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 24, 2026. Predicted dates use 16-day weather forecast through May 10, 2026, then climate normals.