White oak | The Morton Arboretum

Family (English) Beech; Oak
Family (botanic) Fagaceae
Planting site City parkway, Residential and parks, Wide median
Tree or plant type Tree
Foliage Deciduous (seasonally loses leaves)
Native locale Chicago area, Illinois, North America
Size range Large tree (more than 40 feet)
Mature height 50-80 feet
Mature width 100 feet
Light exposure Full sun (6 hrs direct light daily)
Hardiness zones Zone 3, Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
Soil preference Moist, well-drained soil
Tolerances Dry sites
Season of interest mid fall, late fall
Flower color and fragrance Inconspicuous
Shape or form Broad, Irregular, Round
Growth rate Moderate, Slow
Transplants well Yes
Planting considerations Messy fruit/plant parts
Wildlife Game birds, Game mammals, Migrant birds, Small mammals
Has cultivars Yes

More Information

Native Geographic Location and Habitat

White oak is native to the Chicago area, Illinois and North America. C-Value: 5

Bark Color and Texture

The bark is gray to light tan, with thick overlapping plates or thick ridges. Often, large sections of bark on the trunk are smooth due to a harmless fungus called smooth patch.

Leaf or Needle Arrangement, Size, Shape, and Texture

The new leaves emerge pinkish, changing to dark green in summer and wine red in fall. The leaf margins are rounded. The lobes can be small or large.

Flower Arrangement, Shape, and Size

Drooping, male catkins appear in April. Female flowers are inconspicuous tiny spikes in the axils of new leaves.

Fruit, Cone, Nut, and Seed Descriptions

The 1 inch long, single or paired nut is enclosed in an acorn with a warty cap. Acorns ripen in fall and can be considered a litter problem, especially near sidewalks and patios.

Care Knowledge

Plant Care

White oak is the majestic state tree of Illinois. It is a long-lived tree for large landscapes and parks. It does not tolerate wet conditions, so it is best planted in well-drained sites.

Prune oaks in the dormant season to avoid attracting beetles that may carry oak wilt. The roots are sensitive to soil disturbances, such as compaction and construction. It is difficult to transplant due to a taproot.