River Birch, the southernmost birch of the United States, makes its best growth alongside bodies of water or in occasionally flooded bottomlands. It is native to the Atlantic coastal states, southern states, the lower Midwest, eastern Great Plains, and lower Mississippi River valley. In Ohio, it is native mostly in the south-central counties, and sparsely along Lake Erie. However, it is widely planted throughout Ohio and the eastern United States as an ornamental shade tree, prized for its flaky, orange, ornamental bark and rippling foliage in the breeze.
Its rapid growth rate (even in drier soils) allows for quick shade, and it is often propagated and sold in multitrunked form. When found in the open, River Birch may reach 70 feet tall and 40 feet wide as a single trunked tree, and about 50 feet tall and 40 feet wide as a multitrunked tree. As a member of the Birch Family, it is related to the Alders, Hornbeams, Filberts, and Hophornbeams, in addition to other Birches.
Planting Requirements - River Birch prefers moist to wet, rich, deep, acidic soils. It tolerates drier soils but with subsequent leaf drop from the interior of the canopy in summer, and somewhat tolerates soils of alkaline or neutral pH, but often with resulting chlorosis of the foliage. It grows in full sun to partial sun, and is found in zones 3 to 9.
Potential Problems - Aside from drought-induced leaf drop and yellowing foliage due to high pH soil-induced chlorosis, River Birch may have aphids on its new stem and foliage growth, and leaf spot in wet springs (which also leads to leaf drop). However, it should be noted that River Birch is resistant to the bronze birch borer, which plagues the birches of colder climates when they are planted too far south of their natural range (the warmer winters do not kill off the larvae), and is very heat tolerant in summer.