Complete Guide to Black Locust Tree – What you NEED to know


The Black Locust is a deciduous hardwood tree native to Eastern North America that produces rot resistant wood with a high heating value. It will grow 80′ tall by 30′ wide in optimum conditions of full sun and well drained soil. A pioneer species, it spreads via seed and rhizome shoots, becoming aggressive in open areas.

Black Locusts are a good tree for erosion control, land reclamation, and for a durable hardwood that grows extremely fast. They benefit wildlife, can be used for fence posts and hardwood lumber, and produce very fragrant flowers in Spring.

In this article:

Black Locust Tree Facts

  • Growth RateBlack Locust Trees can grow up to 4′ per year when young. Typically 2′ per year once several years old.
  • Black Locust Tree Growing Zone – Hardy from USDA zones 3-8. Check your USDA zone here.
  • A Black Locust Tree can start producing seed as early as 6 years old [1]
  • Seed of the Black Locust Tree is consumed by many species of game bird including grouse, quail, pheasant, and turkey.
  • Black Locust is one of the hardest domestic hardwoods of North America, coming in over 1700 lbf Janka Hardness
  • The scientific name of Black Locust is Robinia pseudoacacia
  • Famous for it’s rot resistance, the heartwood of Black Locust is reported to be one of the most rot-resistant woods in North America

Black Locust Native Range

The primary Native Range of Black Locust is centered in the Appalachian Mountains from Alabama to Pennsylvania, centered in Tennessee and West Virginia. However isolated pockets were also created during glacial retreat in Missouri, Illinois, and Arkansas.

Historical Native Range of Black Locust, Robinia pseudoacacia. [1] Click on image to enlarge

However, due to the strength, rot resistance, and heating value Black Locust trees were planted far and wide by early settlers. The current range covers all of the Lower 48 States in the Continental US, and has also spread around the world. In fact, Black Locust was the first Native North American tree species to be exported to Europe back in 1601. [2]

Current Range Black Locust in North America, courtesy of EDDMapS

Black Locust Tree Reference Table

Common NameBlack Locust
Scientific nameRobinia pseudoacacia
Bloom TimeLate Spring
Bloom Duration1 week
ColorWhite
Bloom SizeWhite flowers that are approximately 3/4″ long, pea-like
CharacteristicsFlowers will be in strings of drooping flowers that hang down and are very fragrant.
Height60′-80′ (18m – 24m)
Spacing/Spread20′-30′ (6m – 9m)
Light RequirementsFull sun
Soil TypesSandy loam, silt loam, loam, clay – must be well-drained
MoistureMoist to dry soils, must drain well
MaintenanceTree will sucker, so must remove new saplings throughout year.
Typical UseOpen areas, fence lines, borders, shade tree
Fauna AssociationsBees, bumblebees, hummingbirds, butterflies, and moths. Game birds eat seeds. Deer browse foliage.
Larval HostOver 50 species of insect larvae, including butterflies and moths
Sowing Depth1/4″ (6 mm)
StratificationNone required. Seed must be scarified.
Native RangeAppalachian Mountains, Ozarks, Isolated driftless regions of United States
Growing ZonesUSDA Zones 3-8
References [1]

Pros and Cons of the Black Locust Tree

Pros / Benefits of Black Locust

Extremely Fast Growth Rate

Depending on the location and site conditions, Black Locust Trees can grow between 18″ and 48″ per year for the first 10 years of it’s life. But even after the first couple of years it can have an impressive 2.5′ growth per year, making this one of the fastest growing native trees. [1] [4]

Erosion Control

By having predominately shallow roots, combined with it’s fast growth make Black Locust one of the best trees to plant for erosion control. It is frequently used in land reclamation at abandoned mine sites. [1] [5]

Rot-resistant, valuable wood

Heartwood from Black Locust trees is a very hard and is extremely rot resistant. This gives it numerous uses in decking, outdoor furniture, fence posts, decking, and furniture. It also has a very high heating value making it a valuable firewood or use in a pellet stove.

Wildlife friendly

Black Locust trees host over 50 species of insects, of which whose larvae will feed numerous songbirds. Additionally, the large amount of seed is food for Wild Turkey, Grouse, Pheasant, and other game birds.

Beautiful fragrant flowers

A grove or thicket of Black Locust Trees can provide one of the most fragrant and aromatic aromas in nature. Should you have the chance, go take in the essence of the Black Locust flowers as they are truly one of the most beautiful smelling flowers this author has ever had the pleasure of experiencing.

Black Locust Tree in Bloom

Cons of Black Locust Trees

Aggressive

In many areas of the world, Black Locust Trees are invasive. The suckering roots of the Black Locust Tree travel far and wide, sprouting new saplings as they go. These trees will spawn thickets of Black Locust if not kept in check.

Thorns

Young saplings and newer growth have small thorns up to 1/2″ long. These thorns are likely a product of evolution to dissuade mammals from browsing the foliage.

Susceptible to heart rot, Locust Borer

Black Locust trees are often attacked by the Locust Borer, which will create tunnels throughout the tree as larvae. These tunnels reduce the value of any lumber, and also provide a vector for heart rot. Heart rot fungus rots the center heartwood of the Black Locust, reducing the potential use and value of any tree.

Black Locust Trees resistance to natural decay / rotting

How long does it take Black Locust to Rot?

Research done by the US Forest Service in Wisconsin has shown Black Locust wood to be in the top 3 performing woods for decay-resistance and durability in both above and in-ground applications. In both decking and ground stake applications, Black Locust performed exceptionally well over an eight-year long study. (Juniper species did outperform it). [6]

Additionally, he standard for rating a wood’s natural resistance to rot is covered in European standards, which classifies species in to 1 of 5 classes, with Class 1 being the most rot-resistant. Black Locust has repeatedly been shown to be a Class 1 or 2, meaning it is one of the most durable woods for resisting natural decay.

Why Black Locust is rot resistant

What makes the wood of the Black Locust Tree so resistant to rot and decay? Black Locust wood is very slow to rot and decay because of a high concentration of Lignin within the heartwood, as well as the presence of two fungus killing flavonoids. These 3 ingredients within the wood of Black Locust make it extremely durable in outdoor applications. [7] [8]

What is Lignin?

Lignin is a complex natural polymer present within wood that resists rotting. It is a key building block for the cellular walls of wood and bark. So, having more Lignin within the cell walls is a good thing for resistance to decay. [9]

Flavonoids – the natural fungus killers

Numerous flavonoids have been identified within the heartwood of Black Locust Tree [6]. But two compounds in particular have been found to provide the wood with it’s famous durability – dihydrorobinetin and robinetin. [7]

Both dihydrorobinetin and robinetin are toxic to the wood-destroying fungi. Research has shown that the amounts of these two compounds increase with age, and also increase the European Standard for Wood Decay EN rating (rot resistance). [29]

The rot resistant of Black Locust is why I chose it for making my bee hotel and super-tall bird-feeder pole. I’m hoping that each last for decades.

leaf cutter bee hotel house 2
This bee hotel and post are made from Black Locust

How to identify Black Locust Trees

Mature Black Locust Trees will grow on average 50′-80′ tall (15m-24m) and have an irregular crown shape. The branching on a Black Locust tree is typically upwards.

Crown of a Black Locust Tree

Trunk/Bark

The Black Locust trunk will reach 1.5′-3′ diameter at maturity. While the bark of the Black Locust Tree will have shallow furrows and rough when young, changing to deep furrows that runs at strange angles and forks. Black Locust bark on mature trees is generally identifiable from a distance, as it is quite unique.

Black Locust Bark

The bark along branches is brown with white spots called lenticels, and new growth will be red in color. As the branch grows and matures, it will become more rough and furrowed.

Thorns

Thorns occur along the smaller branches and twigs which are about 1/2″ long, and occur in pairs. These thorns are quite sharp, and can cause minor injury if you grab a branch or sapling.

Black Locust Thorns

Why Black Locust Trees have thorns

The thorns of a Black Locust Tree are a product of evolution, and act as a deterrent to mammals browsing the foliage. Deer and rabbits are less likely to eat the young branches and trees if they have to contend with sharp thorns.

Leaves

Black Locust Tree leaves are compound alternate leaves in an overall arrangement that is approximately 6-18″ long by ~4″ wide. The individual leaflets are about 1-2″ long by roughly half as wide, with a rounded shape. Leaves will have a light green color early, changing to blueish-green color when mature.

The entire arrangement is known as a compound leaf, and the individual leaves are known as leaflets

In Autumn, the leaves of the Black Locust will turn yellow. In my yard I don’t bother raking leaves, as the leaflets are quite small. They do not smother the grass.

The yellow fallen leaves of Black Locust Tree in Autumn.

Flowers

In late Spring on Black Locust Trees, groups of white flowers will form and hang down from the branches in beautiful arrangements. The overall cluster will be 4-7″ long, and look like dangling cluster of pea-like flowers that are very fragrant. An individual flower is approximately 1″ long with 5 petals that are white in color. Blooming will last for about 2 weeks.

Flowers of the Black Locust Tree

Seed Production

The flowers will give way to seedpods that are approximately 2-4″ long by 1/2″ wide and hang down much like the preceding flowers. Each pod will contain roughly 2-12 seeds that are hard, 1/4″ diameter, and have a rounded shape but very flat.

Seed pods hanging on tree

Pods will begin to ripen in September and split open, dispersing the seed. Pods also can travel a bit by being blown off in wind storms, where they can also open. I have Black Locust trees near my property and often find the occasional pod dozens to maybe 50 yards (m) away from any tree.

Root System

On average the root system of Black Locust Trees is wide spreading shallow lateral roots that can run 50′ or more from a tree. But in drier areas the Black Locust Tree can produce deep vertical roots that reach 20-25′ deep into the ground. [1]

A Black Locust seedling that sprouted from a suckering root (which is attached to the sapling). This tree emerged this year (2021) and is approximately 3′ tall.

But I have personally found Black Locust roots that ran 50-75′ into my lawn from the Black Locust trees that surround my property. So, in typical temperate areas, you should expect shallow roots that extend well beyond the canopy.

How to identify a Black Locust Tree in Winter

Mature Black Locust trees are not difficult to identify in winter due to their irregular shape, distinct bark, small isolated thorns. In Winter it is also likely that you can find seed pods near the drip-line of the tree. Also, Black Locust trees do not survive full shade conditions, the crown or side of the tree should have sun exposure.

Black Locust versus Honey Locust

Similarities between Black Locust and Honey Locust

It is easy to see why people confuse Black Locust and Honey Locust, due to their shared common name. Both are members of the pea family (Fabaceae), and both have compound leaves with like-shaped leaflets. Furthermore, both Black Locust and Honey Locust have thorns and produce seed pods in the fall. But that is where the major similarities end.

Differences between Black Locust and Honey Locust

The 3 main differences between Black Locust and Honey Locust are Black Locusts produces single 1/2″ long thorns in isolation at branch junctures, rough furrowed bark, and flat seed pods 2-4″ long. The trunk of Honey Locust is covered in clusters of large 2-5″ long thorns, has flat-plate style bark, and produces very large seed pods 6-14″ long.

Below I have created a reference table and infographic for identification of both Black Locust and Honey Locust:

Identification Guide of Black and Honey Locust Trees

FeatureBlack LocustHoney Locust
Height60′-80′80′-100′
Crown ShapeIrregular with ascending branchesOpen plume
Bark Rough and deeply furrowed Flat plates with upturned margins.
Thorns1/2″ thorns along trunk and branchesLarge clusters of 5″ thorns that resemble ten-penny nails
LeavesAlternate-Compound, 6-14″ long, odd-pinnateAlternate-Compound, 6-14″ long, even-pinnate or bi-pinnate
Leaflets 1-2″ long by half as wide, oblong, green to blue-green color3/4″-1.5″ long by one-third as wide, yellow-green to dark green color
Petiole (leaf stem)1/8″ (3 mm)1/8″ (3 mm)
FlowerWhite pea-like flowers, arrayed in racemeYellow-green flowers, arrayed in raceme
Seed Pods2-4″ long by 1″ wide, flat6-14″ long by 1″ wide, flat or curled
Seeds1/4″ long, oblong or round, flat3/8″ long, round, flat
Source [1]

Infographic Identification Guide for Black Locust versus Honeylocust

Click on image to enlarge

Grow and care for Black Locust Trees

How to care for

Black Locust trees do not need special care once established. They have proven themselves to be adaptable to a wide variety of environments and climates. If you plant a Black Locust Tree in a location they prefer, basically no care will be required.

Sunlight Requirements

The sunlight requirements for Black Locust Trees is what is known as full sun, which is at least six hours of direct sunlight per day. Black Locust Trees are intolerant of shade.

In general you will not find Black Locust Trees within mature forests, but only on the perimeter or edge. This is because most other deciduous trees will grow taller than Black Locust, and thus shade them out. Oak, Maple, Pine will all out-compete Black Locust, so if it cannot get the sunlight it requires, it will die. [1]

Moisture Requirements

Black Locust Trees prefer moist to medium moist soil that drains well. In general, Black Locust Trees do not like dry or drought prone locations.

If you are unsure about your soil, you can learn to test your soil drainage here.

Soil Requirements

Black Locust Trees are very adaptable in that they can grow in a wide variety of soils as long as they drain well. But in general sand-loam or silt-loam soils will be better than clay for Black Locust Trees.

You can learn to check what type of soil you have here and here.

Maintenance

As a general rule Black Locust Trees do not require special maintenance. The Autumn Leaves are small enough where they don’t even need to be raked up, as they are too small to smother the grass. You may wish to prune your tree though, but just make sure you do so when insects are not active, such as Winter.

But, eventually the lateral roots will begin producing saplings as off-shoots from the root. These saplings will need to be mowed periodically if they are not wanted.

How to grow Black Locust Tree from seed

Black Locust Trees are easy to grow from seed. There are no cold-stratification requirements, but seeds will need to be scarified in order to allow for germination.

Seeds of the Black Locust Tree

Scarify Black Locust Tree seeds by rubbing them on sandpaper, or using a hot water treatment. [10] In my own experiments I have found sandpaper to be more effective. But I will relay both methods here:

Scarification by sandpaper

For sandpaper, rub the seed over the sandpaper until you notice a white spot on the seed. This white spot indicates that the hard outer shell of the seed has been worn away by the sand paper. Soak the now-scarified seed for 24 hours to reduce germination time.

A Black Locust seed I scarified with sandpaper. Note the small white spot where the coating has been removed.

Scarification by hot water

To perform this method you will need a small container, water, and some seeds. Bring a small amount of water to a boil on a stove. Then, remove the water from the heat and wait about 30 seconds. Then, pour this water into a coffee cup with the seeds inside. Allow the seeds to soak for 24 hours.

If at the end of 24 hours you can’t noticeably see that the seeds are larger, this means that they probably did not imbibe water. You should repeat the hot water soak again.

Planting Black Locust Tree Seeds

Fill a large container with moist potting soil. Then, scarify the seeds and soak them for 24 hours. Plant the now-scarified seeds approximately 1/4″ deep. If the seeds were properly scarified, you can expect germination within a few days.

Black Locust Seedlings, about 1 week old.

Raise the seedlings until they develop several sets of true leaves, then transplant them to their final location. The young seedling/saplings should be protected from deer and rabbits.

Wildlife, Pests, and diseases of Black Locust Trees

Fauna Associations of Black Locust Tree

Insects

The Black Locust Tree is ecologically valuable as it feeds over 70 species of insects including beetles, borers, galls, walkingstick, leaf feeders, sucking insects, seed beetles, and over 15 species of moth. Some of these insects are quite damaging such as the Locust Borer and the Locust Twig Borer. [11]

Locust Twig Borer in action

Pollinators

The flowers of Black Locust Tree are mainly pollinated by bumblebees. However, Hummingbirds, butterflies, honeybees, and moths have been documented to visit the flowers. [12] Although the butterflies and moths are not effective at pollinating, just nectar feeding.

Black Locust Trees host several moth species including the Black-Spotted Prominent, Black Zale, Honest Pero, Locust Underwing, Locust Leafrolle, and the Orange Wing.

Mammals

Black Locust Trees and their seeds are toxic to most mammals. However, Deer will occasionally browse the foliage and eat saplings. Squirrels and chipmunks will sometimes eat the seeds as well.

The dense thickets of Black Locust that often form in abandoned areas provide excellent cover for Deer, Coyote, Fox, Skunk, game birds and other woodland mammals.

Birds

The seeds of the Black Locust Tree are a source of food for larger birds such as Bob-White Quail, Turkey, and other game birds. Additionally, the heart rot fungus, while damaging to the tree makes it an excellent habitat for woodpeckers to build cavity nests, such as the Pileated, Flicker, and Yellow or Red-bellied woodpeckers. [1] [13]

Black Locust Trees are toxic to dogs, cats, and horses

The bark, seed pods, and leaves of Black Locust Trees are toxic to dogs, cats, and horses. [14] Symptoms include depression, weakness, vomiting, and respiratory problems. The poisoning will damage the kidneys and liver. [15] If you suspect your pet has consumed any part of the Black Locust Tree, you should seek veterinary care immediately.

Pests

There are two frequent insect pests that can negatively effect the Black Locust and it’s potential lumber value – the Locust Borer and Locust Twig Borer. But there are numerous other insects that harm the tree such as leaf miners, suckers, and various boring insects.

Locust Borer

The Locust Borer is a type of longhorn beetle native to North America that exclusively damage Black Locust Trees. The adults are roughly 3/4″ long, yellow-black in color with a sort of zig-zag stripe pattern on their wings, and straight line horizontal stripes on their head. [16]

An adult Locust Borer on Plains Coreopsis

Lifecycle

Adults are visible from August through October where they frequent Goldenrod flowers during the morning. From afternoon to early evening they can be found laying eggs on Black Locust Tree trunks inside the deep valleys of bark, on or near wounds. [17]

These eggs will hatch and burrow into the bark to hibernate during the winter. When trees begin to leaf out in Spring, you can see sap oozing from the entry holes. In Spring and summer, it will tunnel throughout the tree eventually exiting as an adult in late Summer, completing the cycle.

A Black Locust limb with visible damage from a Locust Twig Borer.

Like most pests and diseases, trees grown on poor sites are more susceptible to attack and damage. It has been noted that the Locust Borer does play an important role in the succession of forests within Appalachia. [18] [19]

Locust Twig Borer

The Locust Twig Borer (Ecdytolopha insiticiana) is a small moth with ~1″ wing span whose larvae will bore into the center of Black Locust twigs, causing damage and twig death. They can be particularly damaging to young saplings. [20]

One day several years ago I was removing some unwanted Black Locust seedlings. I pulled one, and accidentally snapped it off, reveling a Locust Twig Borer larvae inside.

Locust Twig Borer in action. I accidentally interrupted it’s meal.

Fungus

Black Locust is frequently attacked by several fungi while alive that severely rot the heart wood, making lumber worthless. These fungi all gain entry to the tree from wounds, most frequently caused by the Locust Borer and Locust Twig Borer.

There are numerous fungal agents, but three will be presented here that are the most frequent.

Black Locust and Heart Rot Fungus

Heart-Rot Fungus Phellinus rimosus is a fungus that resembles a semi-circle shelf that is generally 2-10 inches diameter and 1-2″ thick. Typically the upper surface is brown to black in color, and the margin will bear spores and be yellowish brown in color to brown. Like most tree fungi, it gains entry to the tree from wounds. [21]

Heart Rot Fungus, Phellinus rimosus, Credit – USDA Forest Service – Region 8 – Southern , USDA Forest Service, Bugwood.org

Another heart-rot fungus that effects Black Locust, Perenniporia robiniophila is a white-shelf like fungus appearing near the base of trees. It’s scientific name robiniophila means ‘locust loving’ but will also effect Hackberry. Like other fungi, it will gain entry from wounds caused by insects. [22]

Perenniporia fraxinea is an inconspicuous white-rot fungus that will severely damage the heart wood, making a tree not mechanically stable. It attacks the base of stems and the trunk base, and while visible fungus/mushroom is present and visible, it is a dark gray or brown color rendering it inconspicuous. Excessive nitrogen in the soil or from pet urine may accelerate the growth, as research indicates the fungus feeds from high nitrogen. [23]

Perenniporia fraxinea – Image By Dragonòt, CC BY-SA 3.0, Link

Aggressive or invasive nature of Black Locust Trees

Black Locust is aggressive or invasive in many sites that it colonizes. As a pioneer species, it is quick to establish itself via it’s rapid growth rate when a sapling, out competing other species.

How a Black Locust Tree spreads

As a general rule, Black Locust Trees will primarily spread via suckering roots that are sent out from the mother tree. These roots sprout new seedlings that rapidly grow, and eventually a dense thicket is formed. This primarily happens in open fields. By year six Black Locust Trees can also produce seeds, furthering it’s spread.

Where Black Locust can be aggressive

Black Locust Trees are most likely to become aggressive in open areas with full sun, where they can form dense thickets from suckering roots. They are not a threat to established forests, as they will not survive in shade of taller trees.

However, once established as the dominant tree, Black Locust will remain in areas outside of it’s native range. Research in Europe has found that other, taller species of tree will not out-compete already established Black Locust forests. This is not an issue in North America, as the natural pests of the tree (Locust Borer, Heart Rot) will naturally thin Black Locust thickets. [24]

How to Control Black Locust Trees

There are two effective methods for controlling Black Locust Trees stop them from spreading in invaded areas. The first, and most environmentally friendly method is a combination of mechanical and herbicide application. The second is strong herbicide application to the basal bark.

But in general, a living Black Locust Tree will continually send out suckering roots that sprout new trees. Additionally, there is some spread from seed dispersal in the fall. The only way to truly stop a Black Locust Tree from spreading is to kill it, or plant it where it’s roots can not expand.

Herbicide Control

As a note for the following two subheadings – were PPE if using herbicide (long clothes, rubber gloves, goggles), only work on calm days, and make sure you follow all directions on the label!

Mechanical / Herbicide Control of Black Locust Trees

The most environmentally friendly method of killing any tree is to cut and paint the stump. You use a chainsaw to cut the tree down, and then immediately apply a coat of 20% Glysophate or Garlon 3A (triclopyr formulation). In this way the herbicide only contacts the tree you wish to kill. [25]

I’ve written a detailed guide on this method here. I have personally killed many invasive trees and shrubs using this method. It is effective, and just about the most environmentally friendly method to kill a tree or shrub that re-sprouts from roots.

Basal Bark Herbicide Application

Successful herbicide application on basal bark has been successfully used for many years on smaller trees with thinner bark. To kill Black Locusts chemically, Garlon 4 (trilopyr mixture) and mineral oil (1:5 ratio) and using a pump sprayer and spray from the base of the tree to a height of 15″ (0.5 m). [25]

When spraying, apply enough herbicide until it begins to run off to the ground. After application, walk backwards from the tree to ensure you don’t pick up herbicide on clothing.

Mechanical Control

Since Black Locust Trees primarily spread via suckering roots, and have the ability to re-sprout, mechanical removal methods are often not effective. If a single mature tree is present, the trees will resprout from the roots. However, if an area contains only small trees, then several years of mowing or goat grazing can be effective control.

Control of Black Locust seedlings in residential yards

If you have Black Locust Trees that border your property you will likely have multiple trees sprout up in the middle of your yard each year. My own yard is surrounded by Black Locust Trees on two sides, and when we moved in late 2016 trees sprouting up were a problem.

Random Black Locust seedling in my yard, standing taller than the grass. It sprouted from one of the numerous surrounding trees.

Regular mowing of your yard will kill any seedlings that sprout up. But I found in times of drought, the tree seedlings will grow while the grass goes dormant. This gives the appearance of, well, small trees growing in your yard.

Removing the suckering roots

I was able to drastically slow the spread of Black Locust Trees in my yard by removing the suckering roots from the Black Locust Trees in Autumn. This was much easier than it sounds. To get rid of the roots, or at least the majority of the root, you need to locate a sapling, use a shovel to expose the root, and start pulling.

It is important to do this in Fall, when grass roots are not as strong, and the ground is generally moist. But locate the root and pull. Follow the root until you can pull no more, then cut it with a pruning saw or spade. You will create a trench, but be able to remove huge amounts of root material.

Doing this greatly reduced the amount of saplings/seedlings that would sprout in my yard. I estimate that some of the roots I removed were over 50′ long. Also of note, the trees that produced these roots were no more than 17 years old at the time of me pulling up the roots.

Where to buy Black Locust Trees or Seeds

Black Locust Trees can be purchased from various specialty nurseries or state forest plant sales. They typically are not available as common big-box garden center stock, as they are not a popular tree.

One supplier who I have purchased from in the past (other species) was coldstreamfarm.net. I have no affiliation with that company, but my experience was very positive.

It can be challenging to locate a reliable source of Black Locust seed. For that reason, it is likely best to become familiar with the tree, and identify your own source.

Uses of Black Locust Trees

Fence Posts

Famous for being rot-resistant, Black Locust Trees have long been sought after and used by farmers for fence posts. There are anecdotes of fence posts lasting for upwards of 80 years. There is a saying that your fence will rust away before the Black Locust fence-post rots.

Lumber

Black Locust wood, planed smooth.

With a Janka Hardness of 1700lbf, Black Locust Wood is one of the hardest commercially available lumbers in North America, rivaling Hickory and second only to Osage Orange. This combined with it’s rot resistance make it particularly suited to certain applications. Additionally, Black Locust Lumber is very beautiful honey colored wood. [26] [27]

Although dimensional lumber availability is somewhat limited, there are several companies that offer it as decking. Frequently small lumber mills have 4×4 fence posts and live edge slabs available. Hobbyist woodworkers can often find value in the appropriate piece of firewood, making tool handles or mallets.

Related ==> Learn to make your own DIY mallet here

Erosion Control

The Black Locust Tree’s rapid growth rate as a sapling combined with it’s propensity to grow in almost any well-drained soil condition make it an excellent tree to stabilize soil banks. It can be utilized on roadsides, slopes, or other disturbed areas.

Land Reclamation

Black Locust Trees have been used extensively in Appalachia, and worldwide for land reclamation at abandoned coal mines and similar sites. Their ability to tolerate poor soil conditions and a wide pH range make it possible to return desolate lands to nature, bringing homes to a variety of insects and wildlife. [5]

Honey

Black Locust Flowers are reputed to produce some of the finest tasting honey in the world. Although the blossoms only last for 1-2 weeks, which will keep that honey in short supply!

Native American Uses of Black Locust Trees

There are 10 uses of Black Locust Trees documented by several tribes, but mainly the Cherokee. These uses included chewing the bark as emetic, crushed root used to treat toothaches, and the bark was also used as a tea (even though toxic). [28]

In addition to several medicinal uses, the Black Locust Tree was used by the Cherokee as a building material for making bows, blowgun darts, fence posts/sills. This further shows the durability of the Black Locust was known for hundreds if not thousands of years.

Value of Black Locust Trees

Depending on the quality quantity of the tree, Black Locust Trees can be worth money. Black Locust Trees can be of value for fence posts and lumber, if the tree isn’t effected by Heart Rot fungus. You can frequently find local and amateur sawmills selling 4×4 locust posts, as well as rough split fence posts.

Read More About Native Trees Here

References:

[1] – Burns, Russell M. Silvics of north America. No. 654. US Department of Agriculture, Forest Service, 1990.

[2] – Sabo, Autumn E. “Robinia pseudoacacia invasions and control in North America and Europe.” (2000).

[3] – EDDMapS. 2021. Early Detection & Distribution Mapping System. The University of Georgia – Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed November 23, 2021.

[4] – Converse, Carmen K., and Update By Nancy Eckardt. “Element stewardship abstract for.” Robinia pseudoacacia (1984).

[5] -Enescu, C. M., and A. Danescu. “Black locust (Robinia pseudoacacia L.)-an invasive neophyte in the conventional land reclamation flora in Romania.” Bulletin of the Transilvania University of Brasov. Forestry, Wood Industry, Agricultural Food Engineering. Series II 6.2 (2013): 23.

[6] – Kirker, Grant, Amy Bishell, and Stan Lebow. “Above and in-ground performance of naturally-durable woods in Wisconsin.” In: McCown, C.; Branton, K., eds. Proceedings, One hundred fourteenth annual meeting, American wood protection association. Birmingham, AL: American Wood Protection Association: 272-277. 2018.

[7] – Reinprecht, Ladislav, Marchal, Rémy. Decay Resistance of Laminated Veneer Lumbers From Black Locust Wood. Wood Research, (2010). https://www.researchgate.net/publication/297289513 Retrieved 23NOV2021

[8] – Adamopoulos, Stergios, Elias Voulgaridis, and Costas Passialis. “Variation of certain chemical properties within the stemwood of black locust (Robinia pseudoacacia L.).” Holz als roh-und Werkstoff 63.5 (2005): 327-333.

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Joe Foster

Hi - I grew up outdoors in nature - hiking, fishing, hunting. In high school I got my first job at a garden center where I learned to garden and landscape. I've been growing plants from seed and designing native plant gardens for over six years. I hope to share some of my knowledge with you! Additionally I am a wood worker / DIY enthusiast. I enjoy designing/building projects (with hand tools when I can!). I hope to give you some tips and useful information!

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