Don’t Plant Black Locust Trees

Aug 8, 2017 | General | 46 comments

Black Locust

Ugh, not another one! This is 2 weeks’ growth. See how much taller it is than the grass?

This is a photo of a tree sucker sprouting from an existing root. The root is attached to a Black Locust tree stump in our neighbor’s front yard. Over 100 feet away. On the other side of our house.

About 2 years ago, our previous neighbor (in the same house) decided to spruce up his property in order to sell it. He thinned out the trees, removing one of his Black Locust trees down to the stump. I thought this was great because that tree had loomed closer to our house and chimney with every passing year. Little did I know that removing it would trigger hordes of tiny Black Locust babies sprouting up across our yard. In fact, we’ve discovered sickly, whitish suckers growing in our crawl space, despite the fact that it is sealed and pitch black inside.

About Black Locust Trees

Black Locust is native to the Southeastern U.S., but has naturalized in many areas. I’ve seen a number of them on roadsides in Seattle and Portland, surrounded by their colonies of suckers. Unfortunately, it’s a handsome, fast-growing tree that produces beautiful clusters of fragrant flowers in spring, which is probably why nurseries still sell it. Our neighbor’s remaining Black Locust casts off white petals that delicately decorate our front yard in early summer, which looks super cool. But that doesn’t make up for the huge negatives which, in addition to the suckering behavior, includes brittle wood prone to splitting during wind storms. Not good!

Black Locust Abatement

Last year I made an intense effort to dig up each sucker and sever the root it had sprouted from. I thought I’d done a great job until around August 1 this year, when I started seeing the sprouts reemerge. I was pretty disappointed to see these popping up in our back yard as well! So I’ve started digging and cutting again. I’ve noticed some of the sprouts are attached to the ends of roots that I had cut last year. I’m hoping to eventually sever and exhaust all the long roots that have made their way across our yard.

A different solution might be to have the stump ground, but I haven’t had the gumption to ask our new neighbor if they’d go for that. They might be into it, because the suckers are invading their yard too. But stump grinders are large machines, and I’m not sure the stump is accessible. In fact, I’m thinking the grinding could spark another suckering frenzy.

Black Locust Tree

A view of the Black Locust tree over our roof. It’s quite pretty, especially in spring. But it’s not worth it, trust me.

The best solution would have been to not plant one in the first place. So if you see one at the nursery, please think twice! Your neighbors will thank you, and you will thank yourself!

Update: February 2019

If you are in the Northwest (or have heard the news) you know we had an insane amount of snow recently. After the last evening of the deluge, my husband and I woke up to a rather large limb of our neighbor’s black locust draped across our overgrown boxwoods, tensioned against our cable line – which was probably the only reason it didn’t slip forward into our living room window.

My husband and neighbor broke out the chainsaws and luckily remedied the situation without any issues. Unfortunately our neighbor lost part of his fence to a second downed limb from the same tree. So…more reasons to not plant this one! Although to be honest, we also lost a few limbs and sustained roof damage from a couple pine trees sited way too close to the house. So maybe be careful what you plant AND where you plant it!

Update: June 2021

Our neighbor had the last locust cut down to a stump in late 2019, and we are STILL getting suckers popping up all over the yard, though there seems to be fewer of them (or maybe that’s wishful thinking?). I’m hoping the roots will be exhausted in the next 2 – 3 years.

Update: June 2023

Black locust suckers emerging through deck boards.

Darnit.

Yep, still getting suckers. Here’s one growing under our deck stairs on the OPPOSITE side of the house from the old locust tree. The sprouts coming through the top are short and stubby due to my attempts to pull them out, which obviously didn’t work. Crawling under the deck landing to pull these is on my to-do list.

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Comments on Don’t Plant Black Locust Trees

46 Comments

  1. Cynthia

    Do you have problems with your neighbors properly maintaining their black locust tree? My neighbors have one planted in their yard and never cut the tree back. It’s now growing over my one story home and the constant breaking branches overwhelm my roof’s drain system.

    Reply
    • Lorie

      Hi Cynthia! That doesn’t sound fun. Our neighbor’s black locust isn’t hanging over our house quite yet, but our own trees tend to overwhelm our gutters on a regular basis so I feel your pain! Maybe it’s worth having a conversation with your neighbor? I’d be inclined to offer to split the cost of the trimming with them. Worst case, I think you have a legal right to hire someone to trim their tree up to the property line, but please check with your city or lawyer (as I’m very much not one). Good luck!

      Reply
      • Ann

        To the person with the black locust problem have you tried cutting the sprout and applying stump killer on it. We use it on maple sprouts

        Reply
  2. chris cousins

    Black locust is prized as a rot resistant wood for fence posts. It is quite expensive to get. Perhaps you should let them grow and sell them.

    Reply
    • Lorie

      Oh funny, I did not know that – sounds like some easy supplemental income! If we had more space I might actually try it. I’d love to try my hand at tree farming!

      Reply
  3. John K.

    Trying to get rid of a Black Locust growing next to our lake. I cut it down last summer thinking that would be the end of it, but lots of new branches sprouted from stump. Now we have lots of suckers growing throughout our yard. Looks like I’ll be digging out a stump this weekend. Never ever plant one of these things in your yard.

    Reply
    • Lorie

      Oh man, isn’t it terrible? I’ve just about resigned myself to pulling new suckers every year. I think our neighbors have been trying to dig their stumps as well and it hasn’t been easy. Good luck this weekend!

      Reply
  4. Matt

    Just moved into a house with a next door neighbor that has a young one growning. Crossbow herbicide seems to be really effective on killing them.

    Reply
    • Lorie

      Hi Matt, thanks for the tip!

      Reply
    • Susan

      Do you drill a hole in the stump and pour the Crossbow in the hole? And if you kill the stump will the roots and suckers die too? Mine is out of control!

      Reply
  5. Jesse Laughlin

    Black locust is a great hardwood for building and fireplace burning. It costs more than oak by the cord.

    Too close to the house I can understand. Thus tree can be great on hillsides and near beaches to hold back erosion, and if let grow to it’s full height is a tall, beautiful

    Reply
    • Lorie

      Hi Jesse, I agree it’s a beautiful tree, and sounds like it can be useful in the right location. Thanks for the perspective!

      Reply
  6. The Apiary Artist

    Black Locust makes a prized honey for beekeepers and their bees in the south! It’s delicious and they are a great food source for many native pollinators who are struggling to find enough forage due to increased development and non-native ornamental plant use in landscaping.

    Like clovers, peas and beans, black locusts are nitrogen fixers and have bacteria associated with their roots that improve the nitrogen levels in the surrounding soil. In addition to honey bees and native bees, hummingbirds and many species of butterflies and moths also visit black locust flowers. Black locust trees are also important host plants for many caterpillar species including that of the silver-spotted skipper and the clouded sulphur. The caterpillars don’t pollinate the flowers, but instead eat the leaves before undergoing metamorphosis into a butterfly or moth.

    If we want to discuss a tree not to plant and to destroy on first sight, it would have to be the Tree of Heaven; Ailanthus altissima and it looks an awful lot like Black Locust and often mistaken for them. In both Europe and America it quickly became a favoured ornamental, especially as a street tree, and by 1840 it was available in most nurseries. They are highly invasive and out competing many of our native plants throughout many areas of the US. So much so, that states have marked them invasive and banning them and are encouraging landowners to report where they’re finding them so the can be destroyed. They have very quickly invaded native ecosystems with disastrous results in the last 100+ years. It’s really sad to see the damage they’ve caused.

    Reply
    • Lorie

      Hi Lyndsey, thank you for the added information about Black Locusts – I had no idea they were nitrogen fixers! It sounds like these trees are indeed beneficial in certain areas. I’m still battling volunteers popping up across my yard even though both original trees are now gone, so it’s still on my personal blacklist. I’m hoping the variety of garden plants I’ve cultivated over the years provide alternative support to the beneficial insects living in our neighborhood. I’ve read briefly about the Tree of Heaven and that one sounds truly nasty. It is sad to see native species crowded out by invasives like that. I feel fortunate to not have to deal with that tree! Thanks again for your comment!

      Reply
  7. Kimberly Viz

    Oh dear! I planted a Black Locust last spring and its about 15 feet tall. Should I dig it up before it gets too established or have I missed my chance? I don’t like the idea of pulling up suckers every year.

    Reply
    • Lorie

      Hi Kimberly, thanks for your question! Geez I hesitate to recommend pulling a plant you’ve already spent the time and trouble to put in your garden. As some other commenters have noted there are a few good spots for Locusts. I’d consult a master gardener in your area through a local plant club, or local cooperative extension to get a second opinion. I don’t think it will start suckering until it’s more mature so you have some time to decide. Hope this helps!

      Reply
      • Mike

        If you kill the tree before you cut it down, it will not send up suckers.
        Drive a copper penny into the tree. Pound it in deep with a hammer. The following year it’ll be dead. Then it’ll be safe to cut down and remove.

        Reply
        • Lorie

          Hi Mike, thanks for the tip!

          Reply
  8. Ray

    We bought an old field that was used as a dumping ground for unwanted landfill. There were no trees at all until a locust appeared a few years ago. I almost ran over it with my lawnmower before stopping. There’s now about 50 trees over the whole acre that all seem to stem from that original tree. We now have bees, birds, shade and much improved soil. We actually wander around the field searching for new ones to make sure we don’t mow them. (Also, there’s no neighbours anywhere nearby)

    Reply
    • Lorie

      Hi Ray, sounds like a perfect environment for this tree – glad it worked out for you and brought nature back to the field!

      Reply
  9. Diane in Ohio

    We have burned the stump of our huge locust tree we removed 8 years ago and we still get suckers throughout the yard. I end up just mowing them over now but we cant seem to ever get rid of them. I would have thought that burning the stump would have killed the root system. That’s one crazy tree!

    Reply
    • Lorie

      I totally agree, it’s crazy! Thanks for your comment!

      Reply
  10. Robert

    Black Locust, if growing within their natural range, surely have some positive aspects. I would, however, warn against planting one on a residential property. They grow quickly so they might seem like the perfect solution to a new home with no trees, but the problems are considerable. I’ve spent untold hours removing unwanted locusts that sprang from just one tree. It is a yearly job. While the wood might be prized in some areas for fence posts, no one in southern Ontario (Canada) where I live would even cut down the tree for free just to take the wood. They also have a tendency to split and break even when they look healthy. If they were on my property I’d do my best to remove every single one. And I do. Unsuccessfully. Hahahaha.

    Reply
    • Lorie

      Ha, you sound just like me! They are STILL coming up in our yard – in fact in July I pulled a long skinny one that grew from the side of our forced air vent into our living room! They grow up in our crawl space. It’s crazy! I’m hoping that by pulling them every year I will eventually exhaust the root system (before it exhausts me, haha). Maybe someday we will win? Good luck!

      Reply
  11. Faten

    So surprised to read these comments!
    I live in Montreal beside a park with a large grouping of these mature trees, 60 to 100, and I have never seen a sucker growing beside any of them. In fact, they are really old, the city may need to remove some of them and the neighbourhood residents are concerned as their so majestic and we love their early June blooming.
    Perhaps due to our cold weather, it is not an aggressive plant here in Quebec, nothing like the nightmare Norway Maple that keep coming every year from my neighbour trees.

    Reply
    • Lorie

      Interesting! Perhaps the weather helps keep them in check in your area – I wish that were the case here because they are beautiful trees with the most wonderful, fragrant white blooms. Good luck with the Norway Maples, we’re lucky to not have that problem, at least in our garden!

      Reply
  12. Darren

    Black locust is one of my favorite trees. It produces excellent wood with many uses as other commenters have stated. It burns exceedingly well as firewood, and has wonderfully fragrant blossoms, which are also quite tasty.

    I had a couple volunteer seedlings show up in my planter boxes last year, and transplanted one to a lonely spot in my yard next to the garage last fall. I wasn’t sure if it would overwinter, but it has come to life with a vengeance this spring, and is now at least three feet tall and wide. The spot it’s in has limited room to spread for suckering due to surrounding with so much concrete on driveways, foundations, etc.

    I plan to spray it a couple times each summer with some Sevin or similar pesticide to hopefully keep the borers at bay.

    We’ll see how it goes!

    And yes, that darned “Tree of Heaven” is by far more aggressive at suckering than any locust I have seen. Those trees are bad news.

    Reply
    • Lorie

      Thanks for your comment Darren, it’s great to hear black locust is working for you, I agree it’s a beautiful tree – and I had no idea the blossoms were edible!

      Reply
  13. CR

    Black locust, as many of you pointed out, is incredibly difficult to eradicate. It is a danger to many habitats and thus is even outlawed regarding planting in certain states. While yes, it is known for its characteristic of being an excellent hardwood for things such as fences, the use of it for that purpose, for the majority of the time, does not appear to outweigh its deleterious impact on surrounding landscapes and environment. It’s pods can lay dormant for years and while their seeds’ reproductive potential is less potent as compared to its suckering, it is a terrible silent “gift” to bequeath any future property owner you sell your home to in the future. If you live near or are on land which livestock or horses graze, it is important to recognize the potential toxicity to animals, in particular horses. Even if you are happy with its presence on your land, your neighbors will suffer from its unwanted presence and proliferation on their land.

    It is challenging to limit the runoff from the chemicals required to manage the newly emerged plants. It often means greatly reduced landscaping options as if other vegetation is placed near them, they can die from the treatment or their presence can obscure early identification of the newly emerging plans.

    As others have mentioned, it’s extensive hardy root system and the trees reaction with suckering to any trauma such as pruning means for the most part, eradicating these trees requires years of patience. Consider it a long war rather than a year or two of management. It consists of diligent observation after the tree has been cut and stump treated by arborist. It means treating/managing new growth on a weekly basis. If you have neighbors anywhere near the tree’s root system., it really makes it your responsibility to let them know and to resign yourself to the idea these trees, desired or not, require removal. They are hazardous and destructive on many levels. Needless to say, they cluster and if they are unwittingly pruned or damaged, a wild, uncontrolled proliferation of clones extending many feet from the trees rapidly appear. These suckers eventually propagate eventually sending out their own suckers. It’s potential exponential growth is breathtaking to watch. They crowd out and kill off other native species and their impact on soil composition appears to outlast their removal.

    Why have I droned on about these? When we purchased out home, we were excited about its landscape and use potential of the side yard. Heck, I even wanted to put a nice bench there for my dad. Being new construction, the topsoil was removed by the developer and the side yard was overgrown. We did not plan a luxurious landscape but something simple and pretty. We used a highly reputable landscaper and the landscape architect excitedly told us a stand of ash trees was growing in the midst of the overgrowth. It was surrounded by other tall growth so we had to take their word for it and why wouldn’t we? Amazingly, she left a stand of 15 to 18 feet high black locusts and had even given them a surrounding bed. We had no experience with these trees and since they were misidentified by the landscaper, we initially thought they were lovely except for the sturdy thorns. I pruned them and much to my horror, I saw thousands of landscaping dollars go up in smoke. I spent a few hours online attempting to identify the tree. Once I identified, I spent hours researching it. It’s a fascinating plant.

    I knew we could not let this reach the neighbors. We had to pay an arborist for removal and leave a large area nearly fallow for years since the chemical runoff (the trees were on a hill) killed off part of the grass and prevented the growth of other nearby vegetation. The trees were removed six years ago and the clones still emerge every year though less and less as each year passes. I’ve spent hours talking to the state university extension program and reading as many reputable state agricultural and arborist/landscaper articles about this tree. The arborist and new landscaper and I reviewed the plan repeatedly. Despite all of this, somehow it shot a runner under the double width drive, at least 6o feet from the prior stand of trees. This appeared a couple years after their removal and it suddenly popped up in a 1 1/2” opening in the driveway directly in front of my garage door. I chuckled because in a way. I really had to respect the tenacity of nature and this species.

    Since this tree cannot be readily eradicated by most standard options (heck even fire doesn’t do it), my personal take on these is never to plant them unless you have contacted your local/state university’s agricultural extension department and reviewed your state’s invasive species list. Even after that, I personally see no reason to plant them except in rare circumstances with highly controllable, constantly monitored settings. They can remain long after you move making it the new owner’s responsibility to manage regardless of the property use (be it a residential, commercial or agricultural property). It can take over prairie land so it just seems more judicious to not proliferate black locusts except as per above.

    I’ve listed some websites below. If these have already been mentioned, I apologize for the redundancy.

    https://mbgna.umich.edu/invasive-of-the-week-black-locust/

    https://dnr.wisconsin.gov/topic/Invasives/fact/BlackLocust.html

    https://www.wnyprism.org/invasive_species/black-locust/

    https://purdue.edu/fnr/extension/black-locust-invasive-in-woodlands/

    https://mortonarb.org/plant-and-protect/trees-and-plants/black-locust-not-recommended/

    https://www.maine.gov/dacf/mnap/features/invasive_plants/robinia.html

    https://smallfarms.cornell.edu/2018/01/black-locust/ (if you are still interested in the perspective of their commercial use)

    https://www.invasive.org/weedcd/pdfs/wgw/blacklocust.pdf

    https://mnfi.anr.msu.edu/invasive-species/BlackLocustBCP.pdf (More comprehensive article with additional links)

    Hope this helps and good luck to everyone trying to eradicate these things or who are engaging in responsible usage!

    Reply
    • Lorie

      Wow thank you so much for your detailed comment and list of resources! That’s so unfortunate that your landscaper misidentified black locusts as ash trees, what a nightmare. Indeed I am still pulling suckers out this summer, a good 3 years after the parent trees were removed. They do seem less numerous and vigorous, but the season is not yet over. Good luck with the battle against them on your property!

      Reply
    • Garden State

      Thank you CR for your detailed account of eradication and management, and Lorie for posting about this tree. My property came with a couple of black locusts, and each of the neighbors have one as well. One is a particularly unhealthy towering tree that has randomly dropped large brittle branches. It’s good to know that if the neighbor ever has it taken down, we’ll have to keep an eye out for a forest of suckers.

      Reply
      • Lorie

        Thanks for your comment, and good luck!

        Reply
  14. Eric

    I live in the NW Philadelphia suburbs. My neighbor across the street had a large black locust cut down several months ago. As a wood turner I snagged a few of the logs and have been rewarded with some beautiful bowls. A few weeks ago I noticed numerous black locust seedlings sprouting 10-20 feet from the stump (which was ground down). After reading up on all the positive attributes I thought about putting a couple of them in my yard, which I am gradually turning into a tree garden/personal arboretum. This blog made me decide against that idea, so thanks to everyone for the detailed and thoughtful contributions.

    Coincidentally, my 20 year old cedar split rail fence was in bad need of replacement and I was just reading up on the durability of black locust posts. I managed to find some (they are in short supply) and now they are going in the ground! Definitely a species that should be supported, but only in the right place.

    Reply
    • Lorie

      Hi Eric, thanks for your comment, I’m glad the conversation has been helpful!

      Reply
  15. Adam

    I’ve recently used black locust wood as a tonewood in a couple of banjos I’ve built- it is a superb tonewood! Crisp, balanced, good bass response, full of depth.

    I’ve also made a few woodworking mallets, and it’s wonderful for as well.

    It also has a neat photo fluorescent aspect. It’s one of a few types of wood that will glow vivid, bright yellow green under a black light. It also ebonizes almost instantly to a consistent black color with iron acetate.

    None of this addresses the problems associated with having one grow in your yard- but it’s a really cool wood to work with.

    Reply
    • Lorie

      Hi Adam, I had no idea that black locust wood would glow under black light, that’s fascinating! Thanks for your comment!

      Reply
  16. Jean

    I live 45 minutes North of Hope, B.C. on an old property that has way too many black locusts trees! Apparently, they were planted here many, many yrs ago as the wood made excellent wagon wheels.

    Reply
  17. Adam

    I feel that black locust is arguably one of the best fire woods to burn in coastal BC. It is comparatively quick to regenerate itself and is therefore a sustainable option to White Oak or Sugar Maple. Its BTU output exceeds both oak and maple and it can grow as much as 4 feet a year according to some. Anyway, due to it’s bore beetle propensity the trees are not used much for furniture and are susceptible to wind break, thus their value as fire wood is pretty natural. They grow like weeds, are incredibly dense and hard, and burn slow and easy through the night leaving red hot coals by morning which allow us to revitalize our fire for the day ahead. Given adequate land and perhaps some competing trees to contained the rhizome growth, black locust could be considered an attractive full-sun option in pastoral settings. I’ve heard their seeds are sources of food for local fauna and their flowers feed the bees. I would hate to have one in my yard in the city. If you have any felled black locust in British Columbia that you want removed, I’m interested.

    Reply
    • Lorie

      Hi Adam, I had no idea that Black Locust is great for fire wood. Sounds like it would be a good choice for folks with large properties looking to live off the land – having a reliable renewable resource for fuel would be really handy. Hopefully another reader from BC with some extra Black Locust will comment in this thread! Thanks for your comment!

      Reply
  18. CR

    Update to 7/1/2022 my post.

    I agree with the recent posts describing the interesting characteristics and wood burning uses of black locust trees. I continue to read about it and still think it’s a fascinating plant. I wish I had an appropriate, large, rural property where I could coexist with them.

    Re: property update. There was a considerable resurgence of the growth the end of last year and this spring. This is despite all our efforts I mentioned in the prior post. We expected continued “flares” but this is sizable. I researched all my options again and reached out to the state ag extension group.

    Has anyone found a way to contain them if given a wide enough berth (ie prevent it threatening adjoining properties) or new advice for eradication? They are spreading through a less accessible area we kept for native species. It’s taking over that area and spreading towards the lawn and a flower bed.

    Other than my discussions about potential biological control with the state agriculture extension, I don’t know what to do.

    Thank you!

    Reply
  19. Leigh Ann

    It is my personal belief that the Black Locust tree is worse that the deadly vines in the upside down in Stranger Things. They are so invasive and will try to destroy your garden. We live next to some woods with Black Locust and between the seeds and the root suckers and saplings it is nearly a full time job trying to eradicate them. I did have very good success utilized Tordon RTU. If you cut a black locust down, squirt it on the canbium within the first 30 minutes and it does a fantastic job killing the root system. I have also used it on smaller roots when I am not able to fully remove the root system. I imagine that I will be fighting this battle for years to come. Please don’t plant this tree anywhere near suburbia.

    Reply
    • Lorie

      Ha, I love the Stranger Things comparison! Thanks for the herbicide tip, I may need to try it. Yet again this spring, I’ve had suckers pop up in our yard far from the tree that was felled several years ago. Sigh. Good luck and thanks for your comment!

      Reply
      • Julia

        NEVER ever plant or cut down a black locust!!! Our neighbour cut theirs down years ago and the root system is wreaking havoc on our yard. They’re known as tree killers (look up what happened in the town of Ladysmith, and those ones weren’t even cut!) Once cut they become fierce monsters that destroy everything in their path. Despite all of our work, we are still getting roots and suckers all through our lawn and neighbours too. They are banned in Ontario and many US States and I wish they’d be banned here in BC. Their roots wrapped around our large trees and took them to the ground. They destroy driveways, pipes and foundations. Never cut or disturb the root system without treating them within 30 mins. Thank you SO much for your blog and helping get the word out about these beasts! They may make good firewood but they destroy other trees, yards and houses if they’re messed with and are virtually impossible to eradicate.

        Reply
        • Lorie

          Hi Julia, yikes it sounds like your situation is much worse than ours! Sorry you are having to deal with it. It seems like the suckers are coming up less and less in our yard every year, so maybe they will eventually start to abate for you? But maybe that’s wishful thinking! Thanks for your comment and good luck!

          Reply
  20. Raúl

    Very nice and super informative article!
    I live in an apartment complex and, in our front garden, there is a black locust. It’s 7 years old, so a very young tree, it gave flowers last year for the first time, if I remember correctly. It is absolutely fascinating how fast these trees grow, it’s already reached a height of approx. 30 ft.
    I live in an urban area, so our front yard is kind of small in size, the locust is practically surrounded by paved surface, there’s not much room for it to spread, unless its roots are strong enough to lift the pavement. However, I did see a small one this spring, right next to it, which was mown with the lawn. I do wonder what things will be like in years, as the tree gets older. I wouldn’t want it to be cut down though, it looks nice and its flowers are a good source of food for many insects. I guess we’ll have to wait and see.

    Reply
    • Lorie

      Hi Raúl! Locusts do have wonderful blossoms. Hopefully in your area the tree is more behaved and you can continue to enjoy its beauty. In our area, we would likely eventually see suckers coming up through the concrete joints. Good luck, and thank you for your comment!

      Reply

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