Tanoak Tanbark-oak

Tanoak appears as a substantial evergreen tree reaching 40 feet or more in the Klamath Mountains and California Coast Ranges, though you may also encounter shrub forms in drier, exposed sites. The thick, leathery leaves are light green and prominently toothed; dense male catkins bloom in late spring and turn rust-colored as they age, while female flowers develop into acorns that require two years

In Western Washington, tanoak thrives in partial shade on moist, well-drained acidic soils; it is highly susceptible to sudden oak death (Phytophthora ramorum), a pathogen that has devastated populations in California. Provide shelter from harsh wind, consistent moisture during establishment, and monitor closely for disease symptoms.