Quercus garryana aka Garry Oak

Quercus garryana is a deciduous tree called Oregon white oak or Garry oak. It belongs to the beech family, Fagaceae. Its native range runs from southwest British Columbia to California. It grows on dry prairies, foothills, and rocky bluffs. This slow-growing oak can live for up to 500 years.

Garden references give a height near 59 feet (18 metres). Other accounts describe trees reaching 80–90 feet (24–27 metres). The crown can spread about 33 feet (10 metres). Open-grown trees form a dense, rounded crown with heavy, crooked branches. Trees in stands have narrower, less even crowns. Young trees may look shrubby for many years. Grey to grey-brown bark has shallow grooves and broad ridges. Stout twigs lose their early hairs as they age. Hairy buds cluster at the twig tips.

The leaves grow in an alternate pattern along the twigs. Each has five to nine rounded lobes, which may overlap. Their upper sides are dark green and shiny. The lower sides are paler, and the blades feel leathery. Fall leaves turn brown, sometimes with gold or dull red tones. Small flowers appear with the new leaves, with May reported for bloom. Male flowers hang in catkins; female flowers form small clusters. Both grow on the same tree, and wind carries pollen. Acorns grow singly or in pairs and ripen that autumn. Their shallow cups cover about a third of each nut.

Grow this oak in sun and deep, fertile loam. It also tolerates heavy clay and lime-rich soil. Young plants can cope with some shade from nearby plants. It withstands drought and prefers dry soil in summer. Summer watering can cause root rot, making irrigated lawns poor sites. Sources place its lower hardiness limit in USDA zone 6 or 7. Cool British summers can leave wood prone to winter frost damage.

This oak serves as a specimen or woodland canopy tree. Surface roots may cause problems, and street-tree use draws mixed views. Wasps cause leaf and twig galls, including large oak apples. Its strong wood has uses in furniture, posts, and fuel. Acorn seeds are edible after water removes their bitter tannins. Ground seeds can thicken soups or make flour. Plants For A Future lists no known hazards.