Quercus bicolor

Swamp white oak is a native medium-sized deciduous tree growing 50 to 60 feet tall and approximately 50 to 60 feet wide with a broad to oval crown and a short trunk. Young trees have a pyramidal habit. The leaves are two-toned in color. The upper half is glossy, medium green to dark green, and the undersides are tomentose with a silvery white appearance. They also have rounded shallow lobes with coarse dentate teeth. This tree is also known for its bark which is thick and divided by furrows and ridges. Flowering occurs in the spring in the form of catkins and short spikes. Brown acorns appear in the fall. The swamp white oak tree is durable and long-living, up to 300 years. It is a member of the Fagaceae or beech family.

This tree is native to the Eastern and Central Midwest of the United States and portions of Canada. It is rare in North Carolina but may be found in about six counties in the Piedmont and only two counties in the Coastal Plain. Typically, the swamp white oak is found in swampy areas, lowlands, floodplains, and along streams and lakes.

The genus name, Quercus, is the Latin name for oak trees. The epithet, bicolor, references the two-tone or two-colors of the upper and lower surface of the leaves. 

The many varieties of Quercus serve as host plants for the larvae of the Imperial moth (Eacles imperialis) as well as a wide variety of butterflies, such as Banded hairstreak (Satyrium calanus), Edward's hairstreak (Satyrium edwardsii), Gray hairstreak (Strymon melinus), White-m hairstreak (Parrhasius malbum), Horace's duskywing (Erynnis horatius), and Juvenal's duskywing (Erynnis juvenalis).

Swamp White Oak prefers full sun, moist to wet acidic soil with a high mineral content, but it is adaptable to drier sites. Due to the root system, it is tolerant of areas that have spring flooding and fairly dry summers. It is tolerant of heat and drought, but sensitive to soil compaction, salt and air pollution. This tree is difficult to transplant and establish. It may also require pruning of lower branches where height clearance is needed.

The swamp white oak may often be confused with the white oak or chestnut oak. The swamp oak does not have deeply cut lobed leaves. The most distinctive feature of the swamp white oak is the branches peeling bark. It also produces a good acorn crop every 3 to 5 years that wildlife love to eat. The acorns are distinguishable by their long stalks.

The swamp oak is best planted in an area along a pond, a stream of other wet or low sites.

Quick ID Hints:

• the bark is thick, black to grayish brown, ridged, and furrowed, and exfoliates in flakes
• branches peeling bark
• leaves are medium to dark green above, silvery white beneath, oblong, lightly lobed with 6 to 10 pairs of coarse dentate teeth
• insignificant male and female flowers in the form of catkins and spikes
• the fruit is an acorn that is light brown to brown with cap that covers 1/3 of the nut and appear on long stalks

Insects, Diseases, and Other Plant Problems: Swamp white oak is susceptible to various insects and diseases, but none are serious. Diseases include anthracnose, canker leaf spots. rust, and blight. Potential insects include caterpillars, borers, leaf miners, oak lace bugs, orangestriped oakworm, buck moth, whitemarked tussock moth, and oak mites.  This tree is highly susceptible to oak wilt. Chlorosis may occur when the pH level is too high. 

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common pests and insects. 

VIDEO created by Grant L. Thompson for “Trees, Shrubs, and Woody Vines for Landscaping” a plant identification course offered by the Department of Horticulture at Iowa State University.