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| ## black locust {#black-locust .Title-Header}                         |
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| *Robinia pseudoacacia* L.                                             |
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| Plant Symbol = ROPS                                                   |
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Contributed by: USDA NRCS New York State Office

![Color image of Black Locust (Robinia
pseudoacacia)](media/image2.jpeg){width="3.0in"
height="2.0in"}**Alternate Names**

False acacia, yellow locust

##### Uses {#uses .Header-3}

Since the wood of black locust is strong, hard, and extremely durable,
it is extensively utilized for fencing, mine timbers, and landscaping
ties. This tree also serves as a good erosion control plant on critical
and highly disturbed areas, due to its ease of establishment, rapid
early growth and spread, and soil building abilities. It has limited
value in wildlife food plots, but provides excellent cover when planted
in spoil areas. Due to its showy aromatic flower, it has often been
planted as an ornamental, but this practice should be discouraged due to
the potential for spread by root suckers. This species has been planted
outside its natural range, and can crowd out other plants, particularly
in sandy soils.

##### Status {#status .Header-3}

Please consult the PLANTS Web site and your State Department of Natural
Resources for this plant's current status (e.g. threatened or endangered
species, state noxious status, and wetland indicator values).

##### Weediness {#weediness .Header-3}

This plant is considered noxious and/or invasive in some states. This
plant may become weedy or invasive in some regions or habitats and may
displace desirable vegetation if not properly managed. Please consult
with your local NRCS Field Office, Cooperative Extension Service office,
or state natural resource or agriculture department regarding its status
and use. Weed information is also available from the PLANTS Web site at
plants.usda.gov.

##### Description {#description .Header-3}

Black locust has a shallow, aggressive root system. The bark of black
locust is deeply furrowed and is dark reddish-brown to black in color.
It has an alternate branching pattern, which creates a zigzag effect. A
pair of sharp thorns grows at each node. They are ½ to ¾ inches long,
and very stout.

The pinnately compound leaves are 8 to 14 inches long, with 7 to 19
short stalked leaflets. These dull green leaflets are ovoid or oval, 1
to 2 inches long, thin, scabrous above and pale below.

The separate male and female plants have sweetly fragrant flowers that
are creamy white with five petals (bean-like) arranged in a pyramidal
spike. They usually bloom in May or June. Heavy seed production can be
expected annually or biannually. The legume type seed is produced in a
flat, brown to black pod, which is 2 to 4 inches long. There is an
average of 25,500 seeds per pound. Although black locust is a good seed
producer, its primary means of spread is by both rudimentary and
adventitious root suckers.

##### Adaptation and Distribution {#adaptation-and-distribution .Header-3}

Black locust's native range follows the Appalachian Mountains from
Pennsylvania to Alabama, and a secondary population exists primarily in
the Ozark Mountains. Black locust is adapted to a wide variety of soil
types, but grows best on sites that are deep, well drained, and derived
from limestone. This tree tolerates a pH range of 4.6 to 8.2. It is
commonly found on south and west slopes in West Virginia.

For a current distribution map, please consult the Plant Profile page
for this species on the PLANTS Website.

##### Establishment {#establishment .Header-3}

Due to the ease of vegetative reproduction, black locust is seldom grown
from seed. If seedling production is desirable, the hard seed coat must
first be reduced or broken to allow germination; this can be done with
sulfuric acid or hot water. Once treated, the seed can be sown on raised
nursery beds or directly on to field sites. Black locust seed combined
in grass and legume mixtures can be broadcast, drilled, hydroseeded, or
aircraft dispersed. Limit locust to 3 pounds per acre in such mixtures.

Black locust is easily propagated from softwood, hardwood, and root
cuttings. Preparing 6 to 12 inch hardwood cuttings, collected while
dormant is often the most effective procedure. This form of cutting
responds well to root-inducing chemicals. Grafting is also a viable
propagation option to maintain varietal integrity.

##### Management {#management .Header-3}

During establishment, protection from weeds and deer are the main
management priorities. Due to the rapid early growth, two years of
protection are usually sufficient. Pre-plant site preparation to control
weeds with tillage or herbicides is recommended, with continued weed
control after planting. Where exceptional deer pressure exists, tubes or
mesh sleeves may be required. Once established this species will not
require active management unless straight trunks are desired for fence
posts- see Pests for information about controlling locust borers.

##### Pests and Potential Problems {#pests-and-potential-problems .Header-3}

There are 2 primary insects inflicting damage on black locust: locust
leaf miner and black locust borer. The leaf miner attacks the tree in
spring, turning the leaves brown by mid-summer or early fall. Overall
tree growth is impacted, but not seriously. The larvae

of the locust borer carve tunnels through the trunk of the tree,
weakening it enough for wind breakage. Planting on good quality sites or
in conjunction with other hardwood species and shading trunks will
discourage infestation by locust borers. Heart rot is the only
noteworthy disease effecting black locust.

##### Cultivars, Improved, and Selected Materials (and area of origin) {#cultivars-improved-and-selected-materials-and-area-of-origin .Header-3}

Ornamental varieties have been developed which are available from
commercial nurseries. The Steiner group black locust was selected and
released by the NRCS Plant Materials Program, for critical area
re-vegetation in the Appalachian region. The three cultivars in the
Steiner group, \'Appalachia\' (VA), \'Allegheny\' (WV), and
\'Algonquin\' (WV) are clonally propagated.

##### Control {#control .Header-3}

Please contact your local agricultural extension specialist or county
weed specialist to learn what works best in your area and how to use it
safely. Always read label and safety instructions for each control
method. Trade names and control measures appear in this document only to
provide specific information. USDA, NRCS does not guarantee or warranty
the products and control methods named, and other products may be
equally effective.

##### Prepared By & Species Coordinator:  {#prepared-by-species-coordinator .Header-3}

*John Dickerson* (retired), USDA NRCS New York State Office, Syracuse,
New York

##### 

##### Edited: 05Feb2002 JLK; 060816 jsp {#edited-05feb2002-jlk-060816-jsp .Header-4}

For more information about this and other plants, please contact your
local NRCS field office or Conservation District, and visit the PLANTS
Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

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*To file a complaint of discrimination write USDA, Director, Office of
Civil Rights, Room 326-W, Whitten Building, 14th and Independence
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*Read about [Civil Rights at the Natural Resources Convervation
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