Oregon Grapes Identification and uses

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Oregon grape, the state flower of Oregon, is a North American native shrub worthy of a spot in a natural landscape. Oregon grape, sometimes called Oregon grape holly because of its spiny leaves, is classified as Berberis aquifolium, or its older name, Mahonia aquifolium. Dwarf Oregon grape bears the scientific name of Berberis (or Mahonia) nervosa. In the state of Oregon, the Governor's home is named Mahonia Hall in honor of this native shrub.

At full height, Oregon grape can reach six feet or more. In nature, it is generally about four or five feet tall due to occasional winter "pruning" by hungry deer and other browsing animals. Its leaves resemble holly leaves, as they are dark green, leathery, and spiny. However, Oregon grape leaves are thinner than holly leaves, and the twigs have a reddish cast. The leaves themselves may have a reddish coloration, particularly if the shrub is growing in full sun.

In the spring, Oregon grape bears clusters of small, yellow flowers which are quite attractive and will draw pollinators. In late summer, the clusters mature into dark purple berries.

Dwarf Oregon grape is less shrubby, and tends to send up a cluster of leafy shoots that give it a form rather like a sword fern. There is also creeping Oregon grape, classified as Berberis (or Mahonia) repens, a low-growing shrub that spreads rapidly by stolons. These, too, bear the characteristic holly-like leaves, yellow flowers, and purple berries.

While the purple berries of Oregon grape are edible, they aren't very tasty straight off the shrub, as they are sour and slightly bitter. The juice does make excellent jelly, since sugar mellows the bitterness.

Native Americans used Oregon grape primarily for the yellow dye that can be extracted from the roots. While the berries were used, they were not a primary food source for native people. The roots and bark were used medicinally, though modern herbalists warn that the plant should not be used casually, as there are toxins in the roots, bark, and leaves. Herbalists today prepare liver tonic from the roots.

Oregon grape is valuable in natural landscapes. It does well on poor soils and requires little water. In its native habitat it grows well on clay soil. It can tolerate full sun, but tends to prefer partial shade. It can even tolerate dry shade, one of the most difficult conditions for for the landscaper to deal with. While deer do occasionally browse on the shrubs in winter if there is no better food available, they more often leave the plant alone, which makes Oregon grape a good choice for gardeners who have roaming deer to cope with.

The flowers are attractive to a variety of pollinators and beneficial insects. Fruit-eating birds feast on the berries, making Oregon grape a key player in wildlife gardens, especially west of the Rockies. Light pruning will fill out its somewhat scraggly appearance and keep Oregon grape trimmed to a size suitable for suburban yards. Once established, tall Oregon grape shrub can spread slowly by underground rhizomes. Both Dwarf Oregon grape and Creeping Oregon grape will spread even more rapidly by stolons, so it's wise to plant these where hardscape will limit their spread, or in places where they are welcome to spread. Wild hedgerows planted for wildlife are a great place to put Oregon grape.

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