Common Name: Black Locust, Common Locust, Yellow Locust, False Acacia
Full sun; medium to dry moisture level; prefers fertile loam but tolerates a wide range of soils including silt loams, sandy loams, sandy and rocky; moderately acid to alkaline pH.
30-50 feet height by 20-35 feet spread; white, pea-like flowers in pendants 8 inches long in late spring; fruit is a flat, smooth, purple-brown seed pod, 2-4 inches long, in fall and persisting through winter.
Growth Rate: Very fast. Freely re-seeds and aggressively suckers from the roots. Can crowd out nearby plants.
Maintenance: Infrequent disease problems but susceptible to a variety of insect pests, especially borers and leaf miners which can make trees unsightly and kill them. Susceptible to wind and ice damage. Long, underground runners can disrupt nearby gardens and become a maintenance problem.
Propagation: Easy from softwood, hardwood, and root cuttings. Difficult from seed. Seldom grown from seed due to ease of vegetative reproduction.
Native Region: Statewide
Often an upright tree with a straight trunk and a narrow, oblong crown, becoming ragged and scraggly with age. Showy, extremely fragrant, wisteria-like flowers. Separate male and female plants and only female plants produce flowers. Branches usually armed with short spines up to 1¼ inch long. Very easy to grow.
It has many bad habits—short-lived, weedy, invasive, produces copious quantities of seed, and sheds branches in high winds. Not for the home landscape. Best used in difficult situations where other trees will not grow well. Extremely adaptable to a wide range of soils and can fix atmospheric nitrogen so it can partially create its own nitrogen supply as well as improve soil quality. Good plant for erosion control and use in highly disturbed areas due to its ease of establishment. Widely used for land reclamation projects. Originally native to the Allegheny Mountains, but it has escaped from gardens and naturalized over much of the U.S. Cultivars available.
Attracts birds, butterflies, bees and hummingbirds.