Oregon grape may seem too common to mention but it has so many merits that it is a go to plant for many situations in the Rogue Valley. Being a native plant, Mahonias can take our winter wet and summer dry and can be very drought tolerant once established. Their thick leathery leaves and spiny edges also make them unpalatable to deer. Most species of Oregon Grape are evergreen but still turn a rainbow of colors in the fall and winter giving them more interest than the average evergreen shrub. The spikes of cheerful yellow flowers emerge early in spring and turn to blue-black fruit that are edible but more appealing to birds than humans. Most varieties grow by underground runners and make a nice colony so best to give them room to shine.
The ones we use the most in the Rogue Valley are:
Mahonia aquifolium (Oregon Grape)- This is the taller species of the native Oregon Grape getting to 6' or more and spreading by underground runners. Looks best as a mass planting in a native woodland situation. They perform best in shade but will take some sun. Can be pruned harshly if getting too leggy and will quickly fill in. Is resistant to oak root fungus so good choice under native oaks, as it also doesn't need much water.
Mahonia aquifolium 'Compacta' (compact Oregon Grape)- This is the Mahonia pictured at left. This variety will stay about 2' tall and make a broad colony. The new foliage is glossy and becoming matte with age. This plant always looks good, staying full to the ground and cheering up the dark days of winter with it's bronzy red winter color.
Mahonia repens (Creeping Mahonia)- This native has a spreading habit and will get about 2-3' tall. It will tolerate more sun the the taller Oregon Grape as well as part shade and is very drought tolerant. It's leaves are usually more matte than the upright Mahonia but get the same yellow flowers and blue fruit. Great choice for mass groundcover or under oaks.
Mahonia nervosa (longleaf Mahonia)-This Mahonia is a little more particular than the others, requiring more shade but still drought tolerant. The leaves are more stiffly upright and bit longer. Makes a nice low shrub or groundcover- around 2' tall for a shady, woodland garden.