Black Locust was once native to the southern Appalachian region of the Eastern United States, but has now spread throughout the world, including all of Ohio. It is valuable as an aggressive, rapidly growing invader species that controls erosion in road cuts, abandoned fields, strip-mined areas, logged forests, and fireswept areas. Initially colonizing by seeds, it also suckers from the roots, forming pure stands and snuffing out competitive weeds and woody plants. Trees of sufficient size are valued for their logs, which make fine fenceposts, poles, or railroad ties due to the anti-rotting properties of the olive-green wood.
Black Locust can quickly grow to 50 feet tall by 25 feet wide, when found in the open. However, high winds coupled with several diseases and pests often limit its potential height. As a member of the Bean Family, it is related to Redbud, Honeylocust, Kentucky Coffeetree, and Wisteria, as well as other Locusts.
Planting Requirements - Black Locust prefers soils that are rich, deep, moist, well-drained, and of variable pH, in full sun to partial sun. However, it is often found under poor soil conditions, especially soils that are thin and near limestone outcrops. It tolerates salts and other pollutants in its water (including strip mine runoff), salt spray on its bare bark in winter, and air pollution. It can grow almost anywhere in zones 4 to 8, provided that it is not near wet soils or shady conditions.
Potential Problems - Black Locust has a long list of potential pests (locust borer can be fatal, and leaf miner can make a tree aesthetically unpleasing by mid-summer) and pathogens (bark canker and trunk rot are the worst) that can make this tree unsightly, unhealthy, or in serious jeopardy on some occasions. In general, Black Locust as a colony survives to be a group of fairly sizable trees, unless the land on which it grows is cleared.