Oregon White Oak
Quercus garryana · Deciduous, Broadleaf, Hardwood, Native
Plant Family
Fagaceae
Tree Category
Shade Tree, Forest Tree, Nut Tree
Variety / Cultivar
None (wild type species)
Hardiness Zones
USDA Hardiness Zones 6 through 9
About This Tree
A massive, slow-growing deciduous tree with a stately, spreading crown. In open settings, it develops a broad, rounded canopy with heavy, twisting branches. It is known for its rugged appearance and extreme longevity.
Leaf Characteristics
Simple, alternate, 3 to 6 inches long; deeply lobed with 5 to 7 rounded lobes; leathery texture; dark green and lustrous on top, paler and slightly fuzzy underneath; turns brown or dull yellow in autumn.
Bark Characteristics
Thick, gray or light brown bark; deeply furrowed into narrow, corky ridges or rectangular plates on mature specimens; provides excellent protection against low-intensity fires.
Growing Information
Origin Region
Native to western North America, ranging from southern British Columbia to central California.
Growing Season
Leaves out in mid to late spring (April/May), flowers in spring with catkins, fruits (acorns) mature in late summer and fall, enters dormancy in late autumn.
Sunlight & Water Needs
Full sun (intolerant of shade); moderate water when young, highly drought-tolerant once established; prefers well-drained loamy soils but adapts to rocky slopes.
Mature Size
Reaches 50 to 90 feet in height with a similar or even wider spread; slow growth rate; can live for 300 to 500 years; trunk diameter can exceed 3 to 4 feet.
Special Characteristics
Extreme drought tolerance once established; historical significance as a primary food source (acorns) for indigenous peoples; resistant to many common pests; distinct 'Garry Oak' ecosystem value.
Wildlife & Ecology
Provides critical habitat for over 200 species; acorns are a vital food source for scrub jays, squirrels, and deer; supports more than 40 species of butterflies and moths as a larval host.