A river birch tree (Betula nigra) is an excellent specimen or accent plant because of its pyramidal form and delicate foliage. It usually has several trunks with papery peeling bark that reveals salmon or rust-colored patches. Although river birch trees are native to the freshwater shores and floodplains of the southern United States, they tolerate drier conditions than other species of birches
River birches may grow up to 90 feet tall, but the average height is 40 to 70 feet, and 25 to 60 feet wide. The lower branches droop on older trees. Young trees have salmon- to rust-colored bark that matures to a silvery gray.
‘Heritage’ river birch grows 50 feet tall with an oval canopy and lighter-colored bark than the species. ‘Fox Valley’ river birch has a dense oval to rounded form and grows 10 to 20 feet tall.
River birches grow best in moist soil in full sun in USDA zones 4 to 9. Their shallow root systems are sensitive to hot, dry soils, but are tolerant of flood conditions. They need acidic soil (pH 5 to 6.5) to prevent chlorosis (yellowing of leaves). Pruning cuts will bleed sap in the spring, so prune when the trees are dormant. River birches are resistant to bronze birch borers. Leafminers and leaf spots are minor problems on the trees.
River birches can be used as shade or street trees, where there is adequate irrigation. They are used in reclamation areas and to control soil erosion. Birds eat the seeds of river birches, while deer and other wildlife eat the leaves and twigs.
An astringent made from the leaves and bark of river birches is used to treat eczema and other skin irritations, according to the University of Florida School of Forestry and Conservation article, “River Birch”. A tonic made from the leaves has been used for gout, kidney stones and rheumatism, while birch tea has been used to reduce fevers. (Never use river birch for these or any ailments, however, without consulting your doctor first.)