A native in the garden: Oregon grape

by Vicky Barney

This spring, everywhere I look - on the trail and in my yard - I see pretty clusters of small bright yellow flowers above holly-shaped spiny leaves, leaves that are mostly rich green and may have spots of orange and red. These small woody shrubs are Oregon grape, named for their edible but tart grape-like berries that appear later in the summer.

The tall form of Oregon grape (Mahonia aquifolium or Berberis aquifolium) is the state flower of Oregon and grows 3 – 6 feet tall. The plant I am seeing is much smaller (1 – 2 feet tall) and is Creeping Oregon grape (Mahonia repens or Berberis repens).

This broadleaf evergreen plant has many names – Oregon grape, Oregon grapeholly, Holly-grape, Mountain holly – which is confusing because it is neither a grape nor a holly. Creeping Oregon grape may also be called creeping mahonia, creeping barberry, or prostrate barberry. Even the Latin names are confusing. The plant is sometimes listed with the genus Mahonia and sometimes with the genus Berberis. Further, botanists are not in agreement whether the creeping form is a subspecies of the taller form, or a species of its own, resulting in yet more Latin names for the smaller form (Mahonia aquifolium var. repens or Berberis aquifolium var. repens).

Once you know the various names, you can find a wealth of information about Oregon grape. Both forms are native to the western United States, and the creeping form is native to our area. It may be found in complete shade, partial shade, and even in open areas. This time of year, you can see the bright yellow flowers along popular hiking trails in this area as well as on the Front Range.

The Creeping Oregon grape in my yard is growing unattended under and around the edges of conifers, chokecherries and serviceberries, sheltered from winter sun and drying winds. It is growing in a sprawling fashion in some areas and is tall and leggy in other places. Some flowers perch on stems over 2 feet tall. It is a wonderful plant for those of us who garden for wildlife: the early blooming flowers provide nectar and pollen for bees and butterflies, and summer berries provide food for the birds.

Creeping Oregon grape is a great plant to actively cultivate in our gardens as well. It tolerates sun, likes the shade, requires very little water once it is established, and is rarely browsed by deer. Pruning will result in shorter, denser plants that make for great ground cover in shady areas. It also can stabilize hillsides with its underground growth habit, and is resistant to wildfire. Medicinal and edible uses are detailed in “Edible & Medicinal Plants of the Southern Rockies” by Mary O’Brien and Karen Vail.

With its striking yellow flowers set against shiny leaves in reds and greens in spring, followed by pretty blue berries in summer, and ending with leaves in all shades of red in the fall, Oregon grape adds interest and value to our yards all season long.

For more information, please check out the following:
Planttalk Colorado - !737 – Creeping Grape Holly
Native Shrubs for Colorado Landscapes – CSU Extension Fact Sheet #7.422
Evergreen Shrubs – CSU Extension Fact Sheet #7.414

Vicky Barney gardens for wildlife and is a member of the Master Gardener Class of 2011.