Northern Red Oak Quercus rubra

Northern Red Oak is a medium-sized, moderate to fast-growing, deciduous tree with a rounded to broad spreading crown that branches close to the ground. It may grow 50 to 75 feet tall and equally as wide. It has green leaves on the upper sides and the undersides are grayish-white. They have 7 to 11 pointed lobes that are sharply pointed at the tips. The fall foliage is reddish-brown. Inconspicuous male and female flowers appear in the spring, and the fruits appear in the fall. The fruits are acorns that are rounded and large. This tree is a member of the Fagaceae or beech family.

The northern red oak is native to Eastern North America and is found throughout the Piedmont and mountain areas of North Carolina. It commonly grows on mesic slopes and well-drained uplands, lower and middle slopes, coves, ravines, or valley floors. 

The genus name, Quercus, is the Latin name for oak trees. The epithet, rubra, means, red.

The northern red oak prefers full sun, moist to dry, well-drained, acidic, fertile, sandy to loamy soils. Once established, they are drought, dry soil, black walnut, and air pollution tolerant. It is easily transplanted.

The bark is smooth on young trees but as it ages, wide, flat-topped ridges and shallow furrows develop. The shallow furrows form a pattern resembling ski tracts. The leaves alternate with 7 to 11 bristle-tipped lobes. Yellow-green, cylindrical, male flowers in spring and small, green, female spikes mature. The tree produces a 0.75 to 1.5-inch acorn with a flat, thick cap that covers about 1/4 of the nut. The acorn requires two growing seasons to reach maturity. Northern red oak generally first bears fruits at 20-25 years but doesn’t produce acorns in abundance until 40-50 years. 

The northern red oak is typically planted for its ornamental value due to its shape and fall foliage. It is also an important food source for squirrels, deer, and birds.  It may be used as a specimen, shade tree, street tree, and in recreational areas.

It is a host plant for the larvae of the Imperial moth (Eacles imperialis), as well as numerous butterflies, including Banded hairstreak (Satyrium calanus), Edward's hairstreak (Satyrium edwardsii), Gray hairstreak (Strymon melinus), White-m hairstreak (Parrhasius malbum), Horace's duskywing (Erynnis horatius), and Juvenalis duskywing (Erynnis juvenalis).

Seasons of Interest:

Foliage:  Summer and Fall                Fruits:  Fall

Quick ID Hints:

• branches and trunk have light gray longitudinal lines
• large leaves, measuring 8 to 12 inches long, 4 to 8 inches wide with 7 to 11 pointed lobes and tips
• leaves are green on the upper surface and grayish-white beneath
• flowers are yellowish-green, inconspicuous, and not showy 
• fruits are rounded, 0.75 to 1.5-inch brown to reddish-brown acorns with a shallow cap

Insects, Diseases, or Other Plant Problems:  The northern red oak has no serious insect or disease problems. It is susceptible to oak wilt and chlorosis (yellowing of the leaves while the veins remain green) which can occur when soil is not sufficiently acidic. Potential insect pests include carpenter worms, timber beetle, red oak borer, and chestnut borer. The most destructive is the gypsy moth that defoliates the trees. Nut weevils, filbert worms, and acorn moth cause damage to the acorns. 

VIDEO created by Ryan Contreras for “Landscape Plant Materials I:  Deciduous Hardwoods and Conifers or Landscape Plant Materials II:  Spring Flowering Trees and Shrubs” a plant identification course offered by the Department of Horticulture at Oregon State University