Oregon White Oak

The Oregon White Oak,(Quercus garryana) is the predominant native deciduous oak of the Pacific Northwest’s original oak savannas west of the Cascades. The tree provides critical habitat for a diversity of wildlife. From mosses and lichens to insects, invertebrates, birds and vertebrates, the diversity of wildlife nourished by the Oregon White Oak is astonishing. Dozens of mammals and native birds including Oregon gray squirrels, deer, black bear, raccoon, opossum, white tailed deer, turkeys, jays, and native songbirds like the slender billed white breasted nuthatch depend on the leaves and acorns of Oregon White Oak for their survival. These magnificent shade trees also increase biodiversity of native insects, lichen. Oregon White Oak and California Black Acorns of white oaks are generally seen as more palatable to wildlife than acorns of the red oaks group.

While they are relatively slow growing, their immense size, dense wood and massive shade producing branches make them more than worth the wait. Growing 80 to 100 feet tall, these trees can live from 250 to 500 years.

As the grassland Savannah tree that it is, this tree thrives in dry summers and should not be watered during dry seasons once it is established, as anything beyond minimal watering in summer can lead to root rot. For this reason, it is best to avoid planting the tree in irrigated lawns or back yards where regular watering occurs.

Oregon White Oak is found on dry rocky slopes and open Savannah both of which are in decline due to urbanization, over-grazing and fire suppression. Evidence suggests native peoples burned out young spreading conifer growth annually to prevent the faster growing conifers encroachment and fire hazards. Without periodic fire, oak the large oaks of open slopes and grasslands will evolve into smaller trees growing in dense oak forests.