The Mahonia Plant

Appearance

• A fully mature mahonia plant can reach as high as 7 to 10 feet with a spread up to 5 feet wide. Naturally leggy, large plants can be straggly and have little defined form. Smaller plants may be pruned to achieve a bushy appearance as they grow. Five to 13 leaves alternate on stems growing out from the branches, each with multiple small stickers around the edges. In early spring, new growth has a reddish color that changes to deep green as summer approaches. The leaves' undersides take on a purplish cast in the winter. Loose clusters of sulfur-yellow flowers emerge in mid-spring, followed by small green fruit the size of blueberries. By mid-summer the fruit has turned blue and may remain on the plant until late winter.

Planting Conditions

• Oregon grape thrives in damp, partially shaded areas similar to its native habitat. Its roots need good drainage, so avoid planting mahonia in heavy clay soil or swampy areas. Before planting, work large quantities of composted, shredded leaves into the ground to gain slightly acidic soil conditions. A layer of bark mulch, replenished each year, maintains soil balance, retains moisture and keeps weeds under control. Place mahonia plants where they are protected from high winds and extended periods of direct sun, which can damage the foliage.

Landscape Uses

• Anchor a woodland garden with shrub-size Oregon grape bushes. Set under the spread of tall firs or pines, mahonia flourishes in soil blanketed by the trees' dropped needles and partial shade. In an urban setting, a row of Oregon grape plants with their prickly leaves makes an effective boundary hedge. Use mahonia as a bold accent in an entryway garden, placed far enough back from the walkway to avoid scratching passersby. Mahonia makes an attractive foundation planting, but should only be used on sides of a structure protected from wind shear. A creeping form of mahonia (Mahonia repens) makes a sturdy ground cover for sunnier areas of the landscape. Just 2 feet high, this spreading evergreen features bright yellow springtime flower clusters, blue fruit in the summer and purple-toned foliage in colder winter months.

Wildlife Attraction

• Include Oregon grape in your butterfly garden to attract native species during the plant's blooming season. The bright yellow flowers also draw hummingbirds that frequent the region. Later in the year, wild birds feast on the the plant's plump, blue fruit. Both the upright Mahonia aquifolium and the low, creeping Mahonia repens provide nectar and food. The plants are generally considered deer-resistant due to the leaves' sharp stickers. Deer may nibble at Oregon grape plants anyway, should other food sources in the surrounding area become scarce in the late fall or early winter.