River Birch, Betula nigra

Summary

Foliage: About 2 to 3 inches long; alternate; deciduous

Height: About 60 feet

Spread: About 40 feet

Shape: Upright oval

Main Features

River birch is a fast-growing shade tree species. As the common name implies, river birch trees tolerate wet soils and are a very suitable species for portions of the landscape that characteristically have moist soil, such as low areas or in poorly drained soils. The nursery industry usually produces this species with multiple trunks (three trees grown in a clump) to maximize the showiness of the beautiful peeling (exfoliating) bark. The bark begins to peel in thin papery sheets on branches that are about 2 inches in diameter; underlying the peeling bark is the living bark in shades of tans, browns, and cinnamon browns. Peeling bark colors are tans, whites, grays, creams, and browns. Seedling-grown trees exhibit a great amount of variation in bark color and peeling characteristics. The bark of mature branches and trunks (diameter of more than 16 inches) does not peel and has gray or blackish irregular scales. There are several river birch cultivars that vary in growth rate, bark color, and foliage characteristics. Heritage® is a very popular fast-growing cultivar with showy bark, handsome foliage, and a good yellow fall foliage color. Other noteworthy clones include City Slicker® (tolerates drought and alkaline soils; handsome bark), Dura-Heat® (heat tolerant; handsome foliage), and the dwarf Fox Valley® (also known as ‘Little King’).

Plant Needs

Zone: 3 to 9

Light: Full sun to full shade (plants will be more open in shady conditions)

Moisture: Average to moist

Soil type: Average

pH range: Acid (very sensitive to alkaline soil)

Functions

River birch serves as a fast-growing shade tree. It is especially suited to moist or wet areas.

Care

River birch is relatively carefree with the exception of occasional leaf spot disease and aphid problems. It is somewhat drought tolerant but will require supplemental irrigation during drought periods. Do not prune river birch in the spring because this species is a “bleeder,” i.e., it will lose large amount of sap from pruning wounds.

Additional Information

Birches that have very attractive white bark, such as paper birch (Betula papyrifera) and European white birch (B. pendula), are quite prone to insect problems in the southern U.S. River birch is resistant to the bronze birch borer which can convert showy white-barked trees to attractive logs for fireplaces. River birch is the most widely distributed birch species throughout the U.S.; it can be found from New Hampshire to Florida and from the east coast to Texas.