Betula lenta, sweet birch — also called black birch or cherry birch for its dark, smooth, cherry-like bark that never peels white — is a native of eastern deciduous forests from New England through the southern Appalachians. Unlike the pale-barked birches, its bark stays dark reddish-brown and only develops shallow plates with age, so it reads more like a smooth-barked cherry than a classic birch in the landscape. Snap a young twig and it releases a strong wintergreen scent, the same compound (methyl salicylate) once distilled commercially from the bark and twigs for oil of wintergreen and used to flavor birch beer before synthetic substitutes took over. Inconspicuous wind-pollinated catkins appear in spring, and the foliage turns a rich gold in fall.
It grows best in the cool, moist, acidic soil of a woodland or forest-edge site and is more shade-tolerant as a young tree than most birches, though it flowers and fruits best with more light. It is generally healthier and longer-lived than paper or gray birch outside of true cold climates, and though it can still host bronze birch borer under stress, it is less commonly afflicted than its lighter-barked relatives. Established trees need little maintenance beyond routine removal of dead or crossing wood.
Fungal leaf spot
Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.
Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.