Tree Questions

Do All Honey Locust Trees Have Thorns?

I remember the first time I saw the thorns on our supposedly thornless honey locust tree. Wickedly sharp, super tough, and featuring three separate points, these thorns were nothing to mess with.

Do all honey locust trees have thorns? Though native honey locust trees are typically densely covered in long, tough thorns, horticulturalists developed thornless honey locust varieties. While they almost always remain thornless, these domesticated varieties have the ability to produce thorns in rare cases.

But that’s just the tip of the iceberg. Keep reading and you’ll find out everything you need to know to the relationship between the honey locust tree and those thorns.

Thorns and the Honey Locust Tree: A Complicated Story

Here we’ll go over how thorns may or may not appear in the various settings that honey locust trees grow. From domesticated thornless stock to the wild and thorny native honey locust, there’s a lot to cover.

Native Honey Locust Trees are Heavily Thorned

Honey locust trees are native to the Midwest and have a natural range that extends as far east as central Pennsylvania. They occur mostly in river valleys and are capable of forming dense thickets that can exact punishment on any living thing that encounters their mess of lengthy thorns.

Every fall honey locust trees produce purple-ish seed pods that contain small seeds. These seeds have an incredibly durable seed coat that allows them to survive long after the seed pods have rotted away or animals have eaten them.

As you can imagine, even the wild honey locust trees are considered somewhat of a nuisance throughout their range. The fact sheet on the honey locust tree provided by the USDA states that their thorns are capable of puncturing the tires of farm implements. It’s no wonder that people were interested in thornless varieties.

Domesticated Varieties are Thornless, but Have the Capacity to Develop Thorns

Years ago horticulturalists developed thornless varieties of the honey locust tree. This proved to make all the difference for the honey locust, as the once threatening tree now seemed pretty appealing.

Relatively fast growing, capable of tolerating the increased pollution of urban and suburban lots, and casting a wonderfully dappled shade below, honey locust trees have been planted all over in many locations. They’re one of the most common trees in our heavily-treed neighborhood in Chicago, and for good reason.

thorns growing from domesticated honey locust branch that was originally thornless

With that said, it is still possible for the thornless honey locust tree to produce thorns in the right (err….wrong?) circumstances. What’s interesting is that the thorny branches don’t necessarily have to exist on the entire tree, and they can be isolated.

And while it’s not impossible for your thornless honey locust tree to start producing thorns, this does appear to be a rare scenario. Just out of curiosity (and perhaps a little jealousy), I’ve casually scoured dozens of other honey locust trees in our neighborhood for thorns. So far I believe I’ve only seen one other tree that produced any thorns.

Offspring Have the Ability to Produce Thorns

If you have a mature, thornless honey locust tree that produces seed pods, you very well likely have small honey locust seedlings all over your lot. This is normal and just part of caring for a honey locust tree, but there is a possibility that a seedling may develop thorns from the start.

For that reason it is a good idea to always take an extra split second to check a honey locust seedling for thorns before pulling it up. These thorns are rather small when the seedling is in its first year, but the thorns on an older seedling could do some damage if you weren’t paying attention.

What to do if Your Thornless Honey Locust Goes Rogue

So maybe you’re like me and you’re looking at a domesticated honey locust tree that decided to sprout some of the vicious thorns they’re known for. What to do now?

First things first, I’m a firm believer that you should do everything you can to mitigate the problem right away. Not only incredibly sharp, the thorns produced by a honey locust tree are incredibly durable. All of this adds up to this reality: these thorns can do some real damage in an accident.

If it’s at all possible, I think it makes the most sense to prune the thorns off of the branch before pruning the branch itself. This will serve to “disarm” the branch and will give you a little bit of peace of mind once you start cutting away. But, there’s one more thing: it’s critical that you not lose the thorns in the lawn if you start pruning them off.

If I recall correctly, the last time I pruned the thorns off of a honey locust branch I utilized both a pair of pruning shears and a pliers. The pruning shears obviously did the cutting while the pliers held a tight grip on the thorn as it was cut off. The odds are you’ll be doing this on a ladder or some kind of platform, so take care to remain as steady as possible.

If you can’t cut the thorns off before pruning the branch off, be sure to exercise caution when making your cuts. Think of it like this: between the dense honey locust branches and the several inch long thorns, you’re essentially cutting down a heavy and spiked club when you prune. So take extreme care to ensure that you’re cutting from a position of safety, as any unexpected movement from the falling branch could turn into a very dangerous situation.

If you go to the effort of pruning off thorny branches, you can expect that your honey locust tree will likely send out more thorny branches in their place. I most recently pruned off the thorny branches from our tree in the early spring, and by the next fall I noticed new thorny growth originating from the same location.

With that said, the thorns on the new growth were not yet so severe, so pruning that new growth off was quite easy. Going forward this will likely be yearly maintenance for our tree.

Concluding Thoughts

Hopefully you found this article interesting and you came away with some value. As much as I tend to despise the several inch long thorns of our honey locust tree, I can admit that I find them somewhat fascinating.

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By Drew Meulemans

I've long admired forests and devote much energy to learning about them and exploring. I enjoy sharing what I learn and wish to inspire others to do the same.