Mahonia

Mahonia is a genus of ornamental and occasionally wild shrubs in the family Berberidaceae, commonly known as Oregon grape or holly-leaved barberry. The genus includes several species native to western North America and parts of Asia. They are valued for their glossy, pinnate leaves, bright yellow spring flowers, and blue-black berries.

Most species are evergreen or semi-ever evergreen and range from about 0.5 to 3 meters in height. Leaves are pinnate with leaflets that have spiny, hollylike margins. In spring, dense racemes of small, bright yellow flowers appear, followed by clusters of blue-black, drupelike berries with a whitish bloom. Berries are edible when cooked and are used in jellies and syrups, though raw fruit is very tart.

Mahonia was historically treated as a separate genus within Berberidaceae, but some classifications merge Mahonia into Berberis. Notable species include Mahonia aquifolium (Oregon grape), Mahonia nervosa (Cascade Oregon-grape), and Mahonia bealei (Leatherleaf mahonia), among others.

The plants are native to western North America from British Columbia to California and to parts of Asia (China, Korea, Japan). They typically grow in woodland margins, forest understories, and rocky slopes, tolerating shade and a range of soils as long as drainage is adequate.

They are widely grown as ornamentals in temperate gardens for year-round foliage, flowers, and berries. They prefer moist, well-drained soils, with some cultivars selected for hardiness and ornamental fruit color. In cultivation, they can be relatively drought-tolerant once established and may serve as understory or border shrubs.

Berries can attract birds; plants are generally pest-resistant but may suffer from powdery mildew in humid conditions and from scale insects. Some species, especially when cultivated outside their native range, have naturalized or become invasive in certain regions.