Oregon White Oak / Garry Oak
Quercus garryana · Deciduous, Broadleaf, Hardwood
Plant Family
Fagaceae
Tree Category
Shade Tree, Forest Tree, Nut-bearing
Variety / Cultivar
Native species (Quercus garryana var. garryana)
Hardiness Zones
USDA Zones 6-9; adapts well to Mediterranean climates with wet winters and dry summers.
About This Tree
A massive, long-lived tree with a broad, rounded crown and gnarled, twisting branches. It features a dense canopy that provides significant shade. In open areas, it develops a spreading, majestic form as seen in the photograph.
Leaf Characteristics
Simple, alternate arrangement; deeply lobed with 5-7 rounded lobes; leathery texture; dark shiny green on top, paler and slightly fuzzy beneath. They turn yellow-brown in autumn.
Bark Characteristics
Light gray to grayish-brown, thick and corky, with deep furrows and narrow ridges or square plates. Often supports moss or lichen growth in humid climates.
Growing Information
Origin Region
Native to Western North America, from British Columbia through Washington and Oregon to California.
Growing Season
Leafs out in late spring (April/May); flowers in spring concurrently with leaves; fruits (acorns) ripen in late summer to fall; dormant in winter.
Sunlight & Water Needs
Full sun preferred; highly drought-tolerant once established. Prefers well-drained soil and does not tolerate significant summer irrigation once mature.
Mature Size
Height: 50-90 feet; Spread: 30-60 feet; Growth rate: Slow; Lifespan: 200-500 years; Trunk diameter: 2-4 feet.
Special Characteristics
Exceptional fire resistance due to thick bark; produces high-quality, hard timber; notable for its ability to grow on dry, rocky slopes where other trees struggle.
Wildlife & Ecology
Keystone species; provides acorns for squirrels, scrub jays, and woodpeckers. Supports hundreds of insect species and provides critical nesting sites for cavity-nesting birds.