# Black Locust (Robinia pseudoacacia)

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

Also called false acacia, yellow locust. Category: Uncommon Yard Trees. Grown from seed by Blue Whale Trees. Web version: https://bluewhaletrees.com/plants/black-locust/

![Black locust (Robinia pseudoacacia) hanging clusters of white pea flowers among its pinnate leaves](https://bluewhaletrees.com/img/plants/black-locust-2-h1610-800.jpg)
*Photo: Cephas, CC BY-SA 4.0, cropped · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File%3ARobinia_pseudoacacia_JRVdH_01.jpg)*

## Facts

- Type: Large tree
- Mature height: 40 to 70 ft
- USDA hardiness zones: 4 to 8
- Grows wild in: Dry uplands, old fields and edges
- Native range: 16 states, north to [Pennsylvania](https://bluewhaletrees.com/tools/native/index.html.md?state=PA), south to [Georgia](https://bluewhaletrees.com/tools/native/index.html.md?state=GA) and west to [Oklahoma](https://bluewhaletrees.com/tools/native/index.html.md?state=OK) ([Alabama](https://bluewhaletrees.com/tools/native/index.html.md?state=AL), [Arkansas](https://bluewhaletrees.com/tools/native/index.html.md?state=AR), [Georgia](https://bluewhaletrees.com/tools/native/index.html.md?state=GA), [Illinois](https://bluewhaletrees.com/tools/native/index.html.md?state=IL), [Indiana](https://bluewhaletrees.com/tools/native/index.html.md?state=IN), [Kentucky](https://bluewhaletrees.com/tools/native/index.html.md?state=KY), [Maryland](https://bluewhaletrees.com/tools/native/index.html.md?state=MD), [Missouri](https://bluewhaletrees.com/tools/native/index.html.md?state=MO), [North Carolina](https://bluewhaletrees.com/tools/native/index.html.md?state=NC), [Ohio](https://bluewhaletrees.com/tools/native/index.html.md?state=OH), [Oklahoma](https://bluewhaletrees.com/tools/native/index.html.md?state=OK), [Pennsylvania](https://bluewhaletrees.com/tools/native/index.html.md?state=PA), [South Carolina](https://bluewhaletrees.com/tools/native/index.html.md?state=SC), [Tennessee](https://bluewhaletrees.com/tools/native/index.html.md?state=TN), [Virginia](https://bluewhaletrees.com/tools/native/index.html.md?state=VA) and [West Virginia](https://bluewhaletrees.com/tools/native/index.html.md?state=WV)). Also recorded, not native, in [Arizona](https://bluewhaletrees.com/tools/native/index.html.md?state=AZ), [California](https://bluewhaletrees.com/tools/native/index.html.md?state=CA), [Colorado](https://bluewhaletrees.com/tools/native/index.html.md?state=CO), [Connecticut](https://bluewhaletrees.com/tools/native/index.html.md?state=CT), [Delaware](https://bluewhaletrees.com/tools/native/index.html.md?state=DE), [Florida](https://bluewhaletrees.com/tools/native/index.html.md?state=FL), [Idaho](https://bluewhaletrees.com/tools/native/index.html.md?state=ID), [Iowa](https://bluewhaletrees.com/tools/native/index.html.md?state=IA), [Kansas](https://bluewhaletrees.com/tools/native/index.html.md?state=KS), [Louisiana](https://bluewhaletrees.com/tools/native/index.html.md?state=LA), [Maine](https://bluewhaletrees.com/tools/native/index.html.md?state=ME), [Massachusetts](https://bluewhaletrees.com/tools/native/index.html.md?state=MA), [Michigan](https://bluewhaletrees.com/tools/native/index.html.md?state=MI), [Minnesota](https://bluewhaletrees.com/tools/native/index.html.md?state=MN), [Mississippi](https://bluewhaletrees.com/tools/native/index.html.md?state=MS), [Montana](https://bluewhaletrees.com/tools/native/index.html.md?state=MT), [Nebraska](https://bluewhaletrees.com/tools/native/index.html.md?state=NE), [Nevada](https://bluewhaletrees.com/tools/native/index.html.md?state=NV), [New Hampshire](https://bluewhaletrees.com/tools/native/index.html.md?state=NH), [New Jersey](https://bluewhaletrees.com/tools/native/index.html.md?state=NJ), [New Mexico](https://bluewhaletrees.com/tools/native/index.html.md?state=NM), [New York](https://bluewhaletrees.com/tools/native/index.html.md?state=NY), [North Dakota](https://bluewhaletrees.com/tools/native/index.html.md?state=ND), [Oregon](https://bluewhaletrees.com/tools/native/index.html.md?state=OR), [Rhode Island](https://bluewhaletrees.com/tools/native/index.html.md?state=RI), [South Dakota](https://bluewhaletrees.com/tools/native/index.html.md?state=SD), [Texas](https://bluewhaletrees.com/tools/native/index.html.md?state=TX), [Utah](https://bluewhaletrees.com/tools/native/index.html.md?state=UT), [Vermont](https://bluewhaletrees.com/tools/native/index.html.md?state=VT), [Washington](https://bluewhaletrees.com/tools/native/index.html.md?state=WA), [Wisconsin](https://bluewhaletrees.com/tools/native/index.html.md?state=WI), [Wyoming](https://bluewhaletrees.com/tools/native/index.html.md?state=WY) and [the District of Columbia](https://bluewhaletrees.com/tools/native/index.html.md?state=DC)
- Sun: Full
- Soil moisture: Dry, Average
- Growth rate: Fast
- Flowers: May to June
- Fruit: Pods, September to October
- First crop: About 6 years
- Mature spread: 35 ft
- Traits: Honey tree, Showy flowers, Drought tolerant, Nitrogen fixing, Wildlife value, Erosion control
- Sold as: Saplings, Seed

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

## Availability

Saplings ship [bare-root](https://bluewhaletrees.com/articles/planting-bare-root-trees-on-arrival/index.html.md) or [in a pot](https://bluewhaletrees.com/articles/a-sapling-in-a-pot/index.html.md), [usually 12 to 18 inches tall](https://bluewhaletrees.com/articles/small-sapling-or-big-transplant/index.html.md), in the dormant season, and their [height and age](https://bluewhaletrees.com/articles/reading-a-nursery-listing/index.html.md) are stated with the price, once available. Live plants ship February to May and October to November. Not priced yet: leave an email on the web page for one email when it is priced, with a code for 10% off the plants in that order, not shipping or tax, or write to captain@bluewhaletrees.com.

In bundles: Honey Tree Trio.

## Notes

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.

## Sources

- [USDA Forest Service, Silvics of North America: black locust](https://research.fs.usda.gov/silvics/black-locust)
- [NC State Extension Gardener Plant Toolbox: Robinia pseudoacacia](https://plants.ces.ncsu.edu/plants/robinia-pseudoacacia/)
- [USDA NRCS PLANTS Database: Robinia pseudoacacia, ROPS](https://plants.sc.egov.usda.gov/plant-profile/ROPS)
- [USDA NRCS Plant Guide: black locust](https://plants.sc.egov.usda.gov/DocumentLibrary/plantguide/pdf/pg_ROPS.pdf)
- [USDA Forest Service, Woody Plant Seed Manual (2008), Robinia chapter](https://rngr.net/publications/wpsm/genera/r/at_download/file)
- [USDA Fire Effects Information System: Robinia pseudoacacia](https://research.fs.usda.gov/feis/species-reviews/robpse)
- [Missouri Department of Conservation field guide: Black Locust](https://mdc.mo.gov/discover-nature/field-guide/black-locust)
- [The Morton Arboretum: black locust](https://mortonarb.org/plant-and-protect/trees-and-plants/black-locust/)
- [Lady Bird Johnson Wildflower Center: Robinia pseudoacacia](https://www.wildflower.org/plants/result.php?id_plant=ROPS)
- [Virginia Tech Dendrology: black locust, Robinia pseudoacacia](https://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=40)
- [NatureServe Explorer: Robinia pseudoacacia](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.157931/Robinia_pseudoacacia)
- [Yuan and others 2014, BMC Evolutionary Biology 14: 53, Selection occurs within linear fruit and during the early stages of reproduction in Robinia pseudoacacia](https://pmc.ncbi.nlm.nih.gov/articles/PMC3998051/)
- [Missouri Botanical Garden Plant Finder: Robinia pseudoacacia](https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=280476&isprofile=1)
- [Eastern Native Tree Society, Maximum Ages for Eastern Trees, the list's thread with Jess Riddle's ring counts of 2008-01-11](https://web.archive.org/web/20220128200143/http://www.nativetreesociety.org/dendro/maximum_ages_for_eastern_trees.htm)

## Read before planting

- [Ten planting mistakes that quietly kill trees](https://bluewhaletrees.com/articles/ten-planting-mistakes/index.html.md)
- [Transplanting young trees: timing, water and protection](https://bluewhaletrees.com/articles/transplanting-young-trees/index.html.md)
- [Protecting young trees from voles, rabbits, deer and squirrels](https://bluewhaletrees.com/articles/protecting-trees-from-animals/index.html.md)
- [Native trees and shrubs that fix nitrogen, and the legumes that do not](https://bluewhaletrees.com/articles/native-trees-and-shrubs-that-fix-nitrogen/index.html.md)
- [What grows back when a field is left alone](https://bluewhaletrees.com/articles/old-field-succession/index.html.md)
- [Six trees not to plant near a house, and what to plant instead](https://bluewhaletrees.com/articles/trees-not-to-plant-near-a-house/index.html.md)

## Related

- Other locusts (Robinia) we grow: [Bristly Locust (Rose Locust)](https://bluewhaletrees.com/plants/rose-locust/index.html.md), [Clammy Locust](https://bluewhaletrees.com/plants/clammy-locust/index.html.md)
- Plants that share its sun and soil: [Black Gum (Tupelo)](https://bluewhaletrees.com/plants/black-gum/index.html.md), [Common Hackberry](https://bluewhaletrees.com/plants/common-hackberry/index.html.md), [Black Cherry](https://bluewhaletrees.com/plants/black-cherry/index.html.md) and [Bur Oak](https://bluewhaletrees.com/plants/bur-oak/index.html.md)
- Under its canopy: [Blackhaw Viburnum](https://bluewhaletrees.com/plants/blackhaw/index.html.md), [Downy Arrowwood](https://bluewhaletrees.com/plants/downy-arrowwood/index.html.md) and [Gray Dogwood](https://bluewhaletrees.com/plants/gray-dogwood/index.html.md)
- Same size, similar character: [Northern Red Oak](https://bluewhaletrees.com/plants/northern-red-oak/index.html.md), [American Elm](https://bluewhaletrees.com/plants/american-elm/index.html.md), [Kentucky Coffeetree](https://bluewhaletrees.com/plants/kentucky-coffeetree/index.html.md) and [Pignut Hickory](https://bluewhaletrees.com/plants/pignut-hickory/index.html.md)
- [Planting-site check](https://bluewhaletrees.com/tools/site-check/index.html.md): for a thrive, struggle or fail verdict on Black Locust, add ?species=black-locust with zone (2 to 10), sun (full, part, shade) and moisture (dry, average, wet) to that address; for example, the verdict for zone 4, part sun and average soil as Markdown is at https://bluewhaletrees.com/tools/site-check/index.html.md?species=black-locust&zone=4&sun=part&moisture=average
- [Companion species for Black Locust](https://bluewhaletrees.com/tools/companions/index.html.md?species=black-locust): the natives that share its ground and the plants that pair with it in a yard.
- [Transplant planner](https://bluewhaletrees.com/tools/transplant/index.html.md?species=black-locust): whether Black Locust can be moved and what the move takes, the root ball, its weight, who can move it and the months, as Markdown at that address (add caliper= or height=, month= 1 to 12 and soil= sandy, loam or clay)
- [Tree growth estimator](https://bluewhaletrees.com/tools/growth/index.html.md): how the height and trunk projections are made; the estimate for Black Locust as Markdown is at https://bluewhaletrees.com/tools/growth/index.html.md?species=black-locust (add height=, years= and site= poor, average or good)
- [Seed sowing planner](https://bluewhaletrees.com/tools/sowing/index.html.md): how Black Locust is sown, in the chart for every species (treatment, cold days, depth, timing); the dated plan for it as Markdown is at https://bluewhaletrees.com/tools/sowing/index.html.md?species=black-locust (add state= and zone= for your own frost dates, method=fridge for the refrigerator route)
- [Pollination planner](https://bluewhaletrees.com/tools/pollination/index.html.md): what Black Locust needs for a crop and how many to plant, in the table for every species; the verdict for 2 of them as Markdown is at https://bluewhaletrees.com/tools/pollination/index.html.md?plants=black-locust:2
- [Planting-window tool](https://bluewhaletrees.com/tools/planting-window/index.html.md): when to plant Black Locust where you live, as a fall and a spring window from the local frost dates; the windows as Markdown are at https://bluewhaletrees.com/tools/planting-window/index.html.md?species=black-locust&state=MO&zone=6 with your own state and zone in place of those
- [Planting-distance tool](https://bluewhaletrees.com/tools/distance/index.html.md): how far Black Locust goes from a house, a septic field, a walk, wires, a property line and the next tree; the distances as Markdown are at https://bluewhaletrees.com/tools/distance/index.html.md?species=black-locust&near=house,septic,pavement,wires,boundary,tree
- [Bloom and fruit calendar](https://bluewhaletrees.com/tools/calendar/index.html.md): the months Black Locust flowers and fruits, in the grid for every species; its own row and the gaps of a planting with it as Markdown at https://bluewhaletrees.com/tools/calendar/index.html.md?plants=black-locust