Bur Oak


Quercus macrocarpa

Leaves: Deciduous.  Leaves are 4-10” long about 3-5”wide. They have 5-9 rounded deep lobes and are extremely variable in shape. Divisions between lobes often come within ¼" of the center of the leaf or midvein. Leaves are much broader towards their point.  Dark green in color with lighter underside. Leaves turn brown in fall, sometimes dull yellow.

Bark/Twigs: Thick, dark gray to gray-brown bark. Bark has a very rough texture and develops deep ridges and furrows even on younger branches. After the first year, stems develop corky ridges.

Flowers/Fruit: Inconspicuous, yellow-green or brown flowers form in thin, hanging clusters. Flowers in late spring as leaves emerge. Acorns are 1-1½” long and round. Acorn cap is fringed and surrounds ½ or more of acorn.

Mature size and shape: Large. 60-80’h with an equal or slightly greater spread. Spreading and rounded shape with a thick, sturdy trunk when older. Somewhat oval or pyramidal when young.

General information/special features: Plant in full sun. Adapts to a variety of conditions and soil types including clay. Drought tolerant due to extensive root system. Lives a long time.

Landscape use and Maintenance: Good large shade tree for open areas. Too large for most residences. Slow growing rate. Average maintenance. Few insect or disease problems. Difficult to transplant.

USDA Hardiness Zone:  3-8

Family/Origin: Fagaceae - Beech and Oak. Native from the Great Plains east throughout the Midwest and Lake States.

Campus use: Common. Large specimens can be found south of Sill Center (Bld 51) and north of Tanner Irish Humanities (Bld 45).