The huge, elegant tree you see standing alone in the field as you drive down the back roads of the Willamette Valley is the Oregon White Oak, Quercus garryana.
Given full room to spread its lush branches, it becomes the epitome of the "mighty oak" of literature. It can eventually command a space seventy-five feet tall and sixty feet wide, with roots growing far beyond the boundaries of its branches. But never fear, in most garden sites it holds itself to much less gargantuan stature, and is very slow-growing, besides, reaching only about twenty-five feet in twenty years.
Though you need a bit of space to house an Oregon oak, it is worth the space if you have it. Laden with the recognizable lobed, classic oak leaves of deep dark green, it produces an abundance of small acorns in summer and fall that are a favorite of many species of birds, making it an excellent choice for a wildlife-attracting garden. Their flowers are of little notice, but the fall foliage is yellow to coppery-orange/brown, and provides an attractive contrast to the fissured gray of the trunk. A deciduous tree with intricate branching, it also provides a sculptural element in winter.
The important thing about including an Oregon oak in your landscape is to site it where it can have mostly full sun, excellent drainage and especially no summer water; some fungus problems and lack of vigor with this plant can often be traced to retained moisture in the soil.
Numerous insects make use of the native Quercus, most of which do little or no damage except sometimes to the acorns, which will not be a bother unless you are trying to use them for food or commercially (and may indeed provide food source for visiting birds). The tiny gall wasp (Cynips maculipennis) is responsible for the small galls that sometimes appear on the underside of the tree's leaves, but they do not seem to negatively impact the health of the tree itself. There are also certain moth larvae for which the oak is the only food source. So the native Quercus is truly a full-spectrum habitat plant!
There are many native shrubs and perennials that grow companionably with Quercus garryana, so you can very successfully use it as the anchor for a more extensive native plant garden, and enjoy it throughout the year and for many, many years.
We offer a great selection of Northwest Natives from spring through fall. The plants featured are highlighted favorites, but they do not represent ALL of the plants we carry. For a more complete list, see our Northwest Native Plant List.