The stately bur oak, native to the Midwest, is a great choice as a shade tree and for specimen plantings in parks, spacious yards, and other large areas. Its massive trunk has gray to brown furrowed bark and its branches bear lustrous dark green leaves that turn yellow-brown in fall. Large acorns with fringed caps attract birds and small mammals. This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region, with updates made according to current research.
Native geographic location and habitat:
C-Value: 5. Bur oak is native to the eastern United States and the great plains. Commonly found in upland savannas.
Bark color and texture:
Mature bark is dark gray to brown with deep furrows. Stems are stout and smooth but young twigs can develop corky ridges.
Leaf or needle arrangement, size, shape, and texture:
Large, alternate leaves are 4 to 10 inch long leaves with five to seven rounded lobes. The terminal lobe can be fiddle-shaped. Leaves are lustrous and dark green above with lighter silvery green beneath. Fall color is yellow-brown.
Flower arrangement, shape, and size:
Male flowers hang down in drooping catkins and female flowers are small spikes in leaf axils. Neither are ornamentally important.
Fruit, cone, nut, and seed descriptions:
Large, 2 inch diameter, fringed caps top the acorns. The conspicuous fringe covers most of the nut. Fruit ripens in the fall.
Plant in full sun in well-drained soil. This tree is adaptable to many soils and drought tolerant once established. Prune oaks in the dormant season to avoid attracting beetles that may carry oak wilt. Oaks do not like compacted soils or having their roots disturbed, so protect the root zone.
List of pests, diseases, and tolerances:
Bur oak can be affected by pests such as leaf galls and kermes scale, anthracnose, bacterial leaf scorch, and powdery mildew. Oak wilt is a serious disease of oaks. Bur oak blight has been found in isolated areas in Illinois.
This plant is a cultivar of a species that is native to the Chicago Region according to Swink and Wilhelm’s Plants of the Chicago Region, with updates made according to current research. Cultivars are plants produced in cultivation by selective breeding or via vegetative propagation from wild plants identified to have desirable traits.
Urban Pinnacle® bur oak (Quercus macrocarpa ‘JFS-KW3):
A narrow and pyramidal (25 feet wide) form of bur oak, the summer foliage is glossy dark green, changing to yellow in fall. Acorns are much smaller than typical for bur oak. This cultivar is resistant to powdery mildew and anthracnose.
Heritage® Macdaniel’s oak (Quercus x macdaniellii ‘Clemson’):
This is a hybrid between bur oak (Quercus macrocarpa) and English oak (Quercus robur). The dark green foliage of this hybrid is resistant to powdery mildew. Fall color is yellow.