Hoyt Arboretum, Portland, Oregon, USA

Common name: bur oak

Family: Fagaceae

Distribution: Canada to Texas- East, South Coast

Habitat: Forest, savannah, bottomland soils, occurring up to 1000m

IUCN Red list: Least concern

Hardiness: Zone 3a -40 to -35 F

Life form: Deciduous tree

Usage: Ornamental shade tree

Comments: Bur oak is a large sized deciduous tree and one of the most majestic of the native North American oaks. Typically grows 60-80’ tall with a broad-spreading, rounded crown. Acorn cups are covered with a mossy scale or bur near the rim, hence the common names. It is native to a variety of habitats in central and eastern North America. Insignificant monoecious yellowish-green flowers in separate male and female catkins appear in spring as the leaves emerge. Fruits are oval acorns (to 1 1/2” long), with fringed, burry cups that extend to approximately 1/2 to 3/4 the acorn length. Acorns are an important source of food for wildlife. Leathery, dark green leaves (6-12” long) with 5-9 rounded lobes are variable in shape, but usually have a pair of deep central sinuses that extend nearly to the midrib giving the leaf a waisted appearance. Fall color is an undistinguished yellow-brown. Twigs sometimes are ridged with corky wings.
Best grown in average, dry to medium, well-drained soils in full sun. Prefers moist well-drained loams, but adapts to a wide range of soil conditions. Good drought tolerance.