Oregon grape

Oregon Grape

Mahonia aquifolium

Botanical Family: Berberidaceae (Barberry family)

Botanical Description

Mahonia aquifolium is an evergreen shrub growing 1-2 meters tall. The glossy, holly-like compound leaves turn reddish in winter. Clusters of fragrant yellow flowers appear in spring, followed by dusty blue-purple berries. The inner bark and roots are bright yellow, indicating the presence of berberine.

Medicinal Actions

Primary actions: Alterative, antimicrobial, bitter tonic, hepatic, anti-inflammatory.

Traditional uses: Native to the Pacific Northwest, used by indigenous peoples and adopted by Western herbalism. Contains berberine, a powerful antimicrobial alkaloid also found in goldenseal. Primarily used for skin conditions (especially psoriasis) and as a liver tonic.

Goldenseal alternative: Oregon grape can substitute for threatened goldenseal, sharing the berberine content.

Body Systems Affected

Integumentary: Specific for psoriasis and chronic skin conditions. Also for acne.

Hepatic: Supports liver function; traditionally used for sluggish liver.

Digestive: Bitter tonic; stimulates digestive secretions.

Immune: Antimicrobial, particularly for GI infections.

Safety Information

Generally safe for short-term use.

Pregnancy/Nursing: AVOID – berberine can stimulate uterine contractions and may affect bilirubin in newborns.

Drug interactions: Berberine may interact with many medications including antibiotics, blood thinners, and diabetes drugs.

Duration: Best used short-term (2-3 weeks) with breaks.

Growing Guide

Hardiness: Zones 5-9.

Light: Partial shade to full shade. Tolerates sun in cool climates.

Soil: Humus-rich, well-drained, acidic soil.

Sowing: Seeds require cold stratification. Easier from divisions or transplants.

Spacing: 1-1.5 meters apart.

Harvesting

Part used: Root and root bark.

When to harvest: Autumn or spring, from established plants.

Drying & Storage

Clean and slice roots. Dry at 40°C (104°F). The yellow color indicates berberine content. Store in airtight containers for up to 2 years.