Creeping Mahonia
Berberis repens
Berberidaceae · vine groundcover · native
Last updated
Creeping mahonia (Berberis repens, Berberidaceae) is a broadleaf evergreen subshrub native to western North America, typically just 2 to 20 centimeters tall though occasionally reaching 60 centimeters. Despite its short stature, roots can extend 3 meters deep. Compound leaves have spiny, holly-like leaflets. Lightly fragrant yellow flower clusters appear in early spring, followed by dark, sour-tasting berries attractive to birds. The plant spreads via shallow rhizomes 1.5 to 5 centimeters below the soil surface.
Creeping mahonia grows in full sun to partial shade on moist, well-drained, acidic soil and becomes drought tolerant once established. It tolerates renovation pruning and is fire-adapted, resprouting after disturbance. Documented diseases include leaf spot, rust, leaf scorch, and powdery mildew; lecanium scale is the primary pest of record. Three cultivars are documented in the trade. Its prostrate habit suits groundcover plantings and erosion control.
Quick Facts
Phenological Calendar
As of April 3, 2026, Puget Sound stations range from 1070 to 1180.6 GDD₃₂. Creeping Mahonia has reached 'flower buds visible' (846 GDD₃₂) and is approaching 'first bloom', predicted around Apr 5.
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 | 'First bloom' | 'Bud break' | 57 |
| Seattle / UW | 1,171 | 'First bloom' | 'Bud break' | 67 |
| Kent / Auburn | 1,111 | 'Flower buds visible' | 'First bloom' | 24 |
| Olympia / Tumwater | 1,106 | 'Flower buds visible' | 'First bloom' | 29 |
| Bellingham / Whatcom | 1,101 | 'Flower buds visible' | 'First bloom' | 34 |
| Tacoma / Puyallup | 1,075 | 'Flower buds visible' | 'First bloom' | 60 |
| Sequim / Rain Shadow | 1,070 | 'Flower buds visible' | 'First bloom' | 65 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ● 'Flower buds visible' BBCH '51' NOW | 846 | '' |
| ○ 'First bloom' BBCH '61' NEXT | 1135 | '' est. Apr 5 (forecast) |
| 'Bud break' BBCH '07' | 1238 | '' est. Apr 9 (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 3, 2026. Predicted dates use 16-day weather forecast through Apr 19, 2026, then climate normals.