The Oregon grape (Mahonia aquifolium) is a broadleaf evergreen shrub that grows well in shadier spots. It originated in western North America and is the state flower of Oregon. It will provide color throughout all four seasons with its green and burgundy foliage, yellow flowers, and purplish-blue fruit.
Oregon grape will be 3- to 10-feet tall and 2- to 5-feet wide. Oregon grape grows best from seed, and those should be planted in the fall. It grows slowly at first, but as it ages, it quickly grows to maturity.
In April and May, clusters of cheery yellow flowers appear. The fruit is a berry that does resemble a grape in shape and color. They are edible but are quite tart and can be used to make jams, jellies, and preserves. Oregon grape can be used as part of a wildlife garden to attract butterflies, bees, hummingbirds, and other birds to your yard.
This shrub can clone itself and spread. On one hand, this can be a useful feature as you can use it to populate a native garden or divide to create new plants. However, this tendency can also lead to the species being invasive in some locations. Your local extension service will know if it is a problem in your area.
|Botanical Name||Mahonia aquifolium|
|Common Name||Oregon grape, Oregon grape-holly, mountain grape, Oregon hollygrape, holly-leaved barberry, tall mahonia, Oregon grapeholly, and Oregon holly-grape|
|Plant Type||Evergreen shrub|
|Mature Size||3-6 ft. tall, 2-5 ft. wide|
|Sun Exposure||Partial shade, full shade|
|Soil Type||Rich, well-draining|
|Flower Color||Yellow that turns to purple berries|
|Hardiness Zones||5-8 (USDA)|
|Native Area||Northern North America|
Oregon Grape Care
The Latin name given to this species is Mahonia aquifolium, and it is part of the Berberidaceae family. The genus name of Mahonia, which honors American horticulturist Bernard McMahon, is given to this plant, though some botanists believe it should be placed in the Berberis (barberry) genus. Additionally, aquifolium means that the leaves are like those of holly trees and shrubs (Ilex), though they are in a different family.
There are many different common names that are associated with this plant, and they are often used for other species of Mahonia, so specify that you want M. aquifolium to help avoid confusion. Even though the common names suggest a connection with the fruit, this is not a true grape (Vitis) or in the Vitaceae family.
The evergreen leaves are sharply toothed like members of the holly genus as noted in the species name. It can be used as a privacy screen to keep unwanted visitors out since the leaves are sharp. These are actually pinnately compound leaves that are up to 12-inches long and made up of several leaflets. When they first appear, they are red. As time passes they turn into a shiny green hue. During autumn, they become burgundy but do not fall off.
While Oregon grape will grow in most any light, it thrives best in partial shade.
The soil needs to be moist with good drainage for optimal growth. It needs to be acidic or at least neutral, as alkaline soils can be problematic.
Water the soil around your Oregon grape weekly, to keep the soil moist.
Temperature and Humidity
This shrub is best suited for USDA Zones 5-8. It is native to western North America. Partial shade is ideal for this species. It can also be grown in full shade or full sun, though too much light can cause foliage scorching. Try to find a planting location that offers some shelter from the wind. Since these are evergreen and do not drop in the fall, the leaves may dry out in the winter if the shrub is hit by wind often.
A multi-purpose 10-10-10 fertilizer offers just the right nutrients for your Oregon grape.
Oregon Grape Varieties
- Mahonia nervosa 'Cascade': displays deep emerald leaves and sprightly, yellow flowers
- Mahonia repens 'Creeping Oregon Grape': offers holly-like foliage that may turn maroon with the seasons
- Mahonia pumila, 'Dwarf western Oregon grape': otherwise known as pigmy Oregon grape, this is a dwarf variety
The Oregon grape does tend to form suckers, so pruning can be used to control these to some extent. It is quite tolerant of pruning and can even be cut all the way down to the ground if you want to give it a fresh start, but usually, it is not in need of much trimming. Pruning should be done in spring once the shrub is done blooming.
How to Grow Oregon Grape From Seed
Oregon grape can grow from seeds that have been stratified for at least several months. Do not let the seeds dry out. Then, sow damp seeds directly into the ground in autumn, before the first frost, 1/4-inch deep into the soil. Cover with 1/2-inch of lightweight mulch, like hay or straw.
Potting and Repotting Oregon Grape
Planted in containers, Oregon grape is a remarkably stunning plant. Mahonia are best grown from seed, and you can set your containers up in the fall. They have deep roots, so plant them in large pots using a rich potting mix. If you choose to plant seedlings, feed them with an N-P-K fertilizer to keep them healthy.
Oregon grape may have signs of pests such as whiteflies, aphids, or scales. Treat with an insecticidal soap.