Are Locust Tree Thorns Poisonous? A Full Answer

Locusts are often seen in gardens as they have rapid growth, but not many people know about their poison. So, are locust tree thorns poisonous, and what to do if you touch one? 

If it’s your concern, we’re here to explain its danger and guide you when you’re in an undesirable scenario with the tree.

Are Locust Tree Thorns Poisonous?

locust tree thorns poisonous
Locust Tree Thorns Poisonous

Yes for back locusts and No for honey locusts. It’s reported that the black locust thorn contains a poison named toxalbumins.

It causes mild or severe pain or even life danger for humans and livestock.

The symptoms include gastrointestinal distress and nervous system disorders.

Meanwhile, honey locust thorns are less poisonous, and the other parts of the tree are useful for livestock, domestic animal breeding, and the medical industry.

What Is A Locust Tree?

It’s a fast-growing flowering tree in the pea family (also known as Fabaceae).

It’s the native plant developing mostly in the mountain forests in Mexico, North Carolina, and eastern North America, where many mash grass types grow, and some are ornamental trees for landscaping.

Their leaves are green in the spring season and gradually become dark brown.

They usually live long (more than a hundred years), obtain harder wood than several strongest deciduous trees, and have an average growth of 10 feet.

Besides the solid, durable wood, locusts have vibrant foliage and mildly fragrant white flowers. Some are considered erosion control plants.

Quite often, people may have confusion between species as the genus has more than 10 types. Honey locusts and black locusts (robinia pseudoacacia) are the most common.

How Many Types Of Locusts Are There?

honey locust tree thorns poisonous
Types Of Locusts

As mentioned above, locusts have more than 10 types, but here we’ll only discuss the two most well-known variants.

Black Locusts

All parts of the black locust trees are poisonous, making them a dangerous species.

The devastating toxic inhibits protein synthesis and can cause diarrhea, constipation, horrible pain, soft tissue infection, extensive tissue necrosis, other symptoms, and even death to those who ingest this inhuman poison.

According to the diagnosis of plants, the highest toxicity is found in the bark and seeds. Also, the black locust thorns are poisonous, so you’d better be careful when the trees are around.

However, it has a narrow crown and aggressive roots and is an excellent plant for erosion control. Besides, the tree is also a traditional medicine in India.

Honey Locusts

Though honey locust thorns are poisonous, the rest is safe to consume. It’s a multi-purpose tree species, as some parts are quite helpful in some cases.

For example, domestic livestock tends to prefer to eat seed pods. It’s also used widely in medicines.

Except for the thorns, honey locust trees are not poisonous. That’s why Native Americans used the sweetness of its edible seed pods as a food sweetener.

What Dangers Can Locusts Cause?

Toxic Trees

Usually, those who consume the plant show signs of extreme pain or toxicity. Quite often, while horses and cows are taking a bite of leaves, they can also swallow some poisonous locust thorns. 

Thus, keep the livestock away from these 2-inch-long spines and try to remove the thorny plant if possible.

Walkway Hazard

The locust tree thorn poison can only be toxic if eaten, yet the plant’s growing position can become a source of problems.

When the trees are too close to where there are many passersby, such as the walk away or center of your yard, they can easily hurt people by poking or scratching.

Young children who are as high as the tree canopy can get injured in the eyes by those sharp barbs.

Moreover, people can easily step on the fallen branches full of spines and get poked through a thin shoe.

Inflatable And Plastic Equipment

Sometimes, wind can blow the branches with stout thorns, causing them to fall and make holes in plastic materials used to make some outdoor items for kids, such as Inflatable toys, pools, bounce houses, plastic water slides, etc.

A fallen branch can drop into the water and puncture the ponds and pools with rubber liners.

Plus, it’s easy to get a hole in your equipment if you don’t check the ground for any thorny branches before placing them down.

Anchor the inflatable toys carefully, as they can fly away on windy days and get stuck on the sharp thorns.

Wildlife Habitat

Despite the locust thorn having poison, thorny bushes and trees are favorite places for birds to come as they offer protected shelter.

Locusts can invite new bird colonies to your yard of early spring white flowering trees.

However, it also welcomes crows who will threaten other avian residents and your crops before you have a chance to harvest.

How To Remove The Thorns?

black locust thorn poison
Way To Remove The Thorns

Now you know both black and honey locust tree thorns are poisonous, and it’s better to protect yourself before any accident occurs.

However, there are still some careless moments. Don’t worry! Here are some steps to help you out.

Step 1. Clean the injured parts

The first and foremost action to take is to clean the area as soon as possible with clean water. You can also do it by using antiseptics or sanitizers.

Step 2. Inspect the area

It’s important to identify how deep the black locust thorn is in your skin. If its end pokes out, you can go to step 3. If the dangerous spine is fully inside, go to step 4.

Step 3. Use tweezers

Tweezers work best as a simple and easy way to help you eliminate a sticking-out thorn. Remember to hold the tool to the close and top corners to prevent further injury in the affected area.

Step 4. Apply salve or ointment

Salve does unexpectedly great help to draw out the end of the thorn in most cases. When you see it successfully poke out, go to step 3 to fully pull the spine out.


Are locust tree thorns poisonous? Both can harm your health and other livestock life to some extent, depending on the level of toxicity.

Black locusts’ thorns can cause dangerous forest tree disease, while the honey locust thorn’s poison does not do that much harm to humans though it takes time to heal.

These locust invasive species can easily appear in gardens in the United States.

So, if it’s one of your concerned species, follow a clear field guide to keep an eye on them and remove them if necessary, especially the threatening black variant.

Samuel Mark

Hello I am Samuel. Samuel's Garden is a garden blog where I share my experiences in garden caring and tree growth. Hope you enjoy it!

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