Photo: Cephas, CC BY-SA 4.0, cropped · Wikimedia Commons

Black Locust

Scientific name: Robinia pseudoacacia

Also called false acacia, yellow locust.

Fragrant white flower clusters in May, the source of the lightest and most prized honey in the East.

Be first when black locust is priced

Saplings ship bare-root or in a pot, usually 12 to 18 inches tall, in the dormant season, and their height and age are stated here with the price, once available.

We grow it as saplings and seed. One email when it is listed with prices, and nothing else. Or ask, and we reply with what is ready now. Live plants ship February to May and October to November.

Ask about this plant Email instead

In bundles

Honey Tree Trio

Share: copy link

Honey treeShowy flowersDrought tolerantNitrogen fixingWildlife valueErosion control

Type: Large tree
Mature height: 40–70 ft
USDA zones: 4–8
Growth rate: Fast
Flowers: May to June
Fruit: Pods, September to October
First crop: About 6 years
Mature spread: 35 ft
Sun: Full
Soil moisture: Dry, Average
Grows wild in: Dry uplands, old fields and edges
Native range: 16 states, north to Pennsylvania, south to Georgia and west to Oklahoma
List all 16, and the 33 others
Alabama, Arkansas, Georgia, Illinois, Indiana, Kentucky, Maryland, Missouri, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Virginia and West Virginia
Also recorded, not native, in Arizona, California, Colorado, Connecticut, Delaware, Florida, Idaho, Iowa, Kansas, Louisiana, Maine, Massachusetts, Michigan, Minnesota, Mississippi, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Dakota, Oregon, Rhode Island, South Dakota, Texas, Utah, Vermont, Washington, Wisconsin, Wyoming and the District of Columbia.
Also recorded, not native, in 33 other states (listed above). See what is native in your state

Hardiness zones Find your zone by ZIP code

Black locust fixes nitrogen, grows several feet a year on the poorest ground, and produces rot-resistant wood that outlasts treated lumber. Its blooms are a major honey flow for beekeepers. It suckers and spreads, so give it room or a mowed edge, and site it away from small gardens. A pioneer tree for reclaiming worn-out land. On mine spoil and road cuts it is planted to control erosion, since its spreading roots hold the soil. Best used as a fence-post woodlot or a pioneer for worn-out ground, on the back of the property.

Size, growth and what to expect

Black locust plantations in the Central States grew a foot and a half a year on poor sites and 4 feet or more on good ones. That brackets the nearly three feet a year our growth estimator models for a fast grower. Trees generally reach 40 to 70 feet, or 100 feet on the best ground, and live about 90 years. The oldest known has been ring-counted to 146.

Seed begins at about age 6, with a good crop every year or two and the heaviest between 15 and 40 years. Fragrant white pea flowers hang in clusters 5 to 8 inches long in May or June, and the flat pods, 2 to 4 inches long, ripen in September and October. The yellow wood is hard, strong and naturally rot resistant. The name false acacia records its likeness to the true acacias.

It grows wild in two blocks, the Appalachians from central Pennsylvania and southern Ohio south to northern Georgia and Alabama, and the Ozarks of Missouri, Arkansas and Oklahoma. It has since spread across the country. It will not stand compacted or poorly drained soil.

How to grow Black Locust

Black locust wants full sun and dry to average ground. Gravel, subsoil and worn-out pasture all suit it. Trees grow tall with brittle limbs, so keep one 35 feet from the house and clear of power lines. Set trees 20 feet apart.

Plant in the dormant season. Saplings ship bare-root or potted; open a hole twice as wide as the roots and no deeper, set the root flare level with the ground, and refill with the soil you dug. Seed has a stony coat, so pour just-boiled water over it, soak it overnight, and sow in spring. Mulch a ring that stops short of the bark, and stake only if wind rocks the stem.

Water it through the first dry summer. Rabbits gnaw the smooth young bark and deer browse the tips, so keep a tube or cage on for two winters. Train one leader early, because narrow forks split in storms.

Bees carry the pollen, and a lone black locust can set seed with its own, but more of those seeds abort. A second tree nearby improves the crop. Young shoots and suckers carry paired spines, so wear gloves. Roots that are cut or mowed sprout freely. Locust borer tunnels stressed trunks, and the leafminer browns the crown by August without lasting harm. Bark, leaves and seed are poisonous to livestock. Maine, Massachusetts, Minnesota and Wisconsin ban or restrict its sale, and New York allows it only under an invasive-species label, so we do not send it to those five states.

Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them.

Sources (14)