Walnut or Juglans belongs to tree species of the genus Juglans. It is the seed of the tree which is known as the walnut. They are medium to large trees and can grow anywhere between 30-140 feet tall. All varieties of this species are deciduous in nature.
Let’s take a look at some of the ways of killing Walnut trees as well as their root system.
How to Kill Walnut Trees?
Some of the most popular killing methods for Walnuts are:
- Foliar Spray
- Cutting the tree down and treating the stump with Herbicides
- Gridling or ring barking
- Basal Bark treatment
- Injecting the tree with killing chemicals
- Cut surface treatment
I would refer back to my more detailed tree-killing article if you are interested in learning more about these tree-killing methods.
The best way to kill a small Walnut tree
A small Juglans tree is less than 10 feet tall. The easiest method to kill the tree in this growth stage would be to simply cut it down and treat the stump with a herbicide like Tordon RTU from Amazon to prevent any further growth (Affiliate link).
On the other hand, if the diameter of the tree is less than 7 inches, you can also go for Basal Bark Treatment.
Basal bark treatment
First of all, wear protective gear while using this method. I always advise reading manufacturers’ instructions before using the herbicide.
See my recommended products list here.
- For this method you will need a sprayer for spraying the chemical, a strong herbicide and an oil-based solvent.
- Choose an herbicide that contains Trycloper or Trycloper Ester as the main chemical. Even Imazapyr based herbicides can be a good option. This one from Amazon is Effective. (affiliate link)
- The solvent to mix the herbicide in would be diesel, basal oil, fuel oil or kerosene.
- The ideal proportion for mixing should be 1 part herbicide and 4-part solvent, so about 20-25% concentration.
- Make sure that the tree is not wet while performing this technique as the oil-based solvent is hydrophobic, which means it will not be absorbed as effectively.
- Once you have the solution, spray the bottom 20 inches of the Juglans with this solution and let it dry out.
- Once the first layer has been absorbed, repeat the process again for faster absorption.
Some types of herbicides in the market can directly be used for this method without needing to mix with a solvent, like ‘Pathfinder II’. There are a lot of varieties in the market, so make sure to read the label before using it.
The best way to kill a large Walnut tree
A large Juglans tree can grow to about 130 feet tall. The preferred method to use here would be girdling and chemical injection. Alternatively, you can also simply cut down the tree, but you might need professional help here because of the large size.
Girdling
Ringbarking or Girding would be the easiest and the most efficient method for killing a large Juglans as it will stop the nutrient flow within the tree slowly killing the tree over time.
- You will need to either get a hatchet, hammer and chisel or chainsaw to cut and pry the bark.
- Remove a ring of bark around the entire tree, about 4-8 inches wide.
- For better efficency spray concentrated herbicide along the exposed bark.
Additional reading: Why Do trees Have Bark
Chemical Injection Method
- You will need a drill and a herbicide for this method.
- Simply drill holes at a downward angle, 2-3 inches deep along the circumference of the tree, about 2-3 feet above the ground.
- Inject a strong herbicide like Roundup or Tordon RTU into these holes and let it absorb. You can this herbicide from Amazon.
- After the chemical is absorbed, inject more herbicide into these holes to increase absorbiton.
- If the tree has multiple trunks, drill holes and apply herbicide to each of the trunks.
What’s the best time to kill Walnut?
Although you can use the above-stated methods any time of the year, the preferred season to kill the Walnut trees would be winter or early spring depending on the method. This way the tree won’t have any nutrients to grow new leaves and seeds during spring.
You should use Girdling in late winter or in early spring. Chemical injection and basal bark treatment should be used when the nutrient flow within the tree is fully active – in early spring.
Should you hire a professional tree removal service?
If Junglans tree is small, most of the time, it is easy to kill the tree and get it removed, even as a DIY project.
On the other hand, if you are dealing with a mature tree, things get more complicated. You have to take into account a number of things before killing a tree. For example, where the tree is located, do you need to remove the tree and the stump ground completely, or do you just need to kill the tree?
In most cases removing a mature tree on your own can turn out to be more costly than hiring a professional service provider who would take care of all necessary steps to completely kill the tree and its root system.
If you are wondering how much tree removal might cost, read my article about it.
Frequently Asked Questions
Can you kill a Walnut without cutting it down?
Yes, the preferred methods for killing a Junglus tree without cutting it down would be Basal Bark Treatment when the tree is small and Girdling along with chemical injection when the tree is on a bigger side.
How to remove Black Walnut seedlings?
The easiest way to get rid of Black Walnut seedlings would be completely uprooting the shoot and spraying a bit of herbicide on the area.
Can Salt be used to kill a Juglans tree?
Salt can be used to kill a Junglans tree if it is small. Salt will stop the potassium and magnesium flow inside the tree but it won’t be as effective on a mature tree with an established root system.
Conclusion
To kill a Junglans or walnut tree, you can use basal bark treatment if the tree’s trunk is less than 7 inches in diameter. For bigger trees, you should use girdling and chemical injection or both. Alternatively, you can cut the tree down and treat the stump with a concentrated herbicide to prevent further growth.
Recommended reading:
Hi!
I am the guy behind Theyardable.com. I grew up on a homestead and I am here to share the knowledge I have and things I learn while living in the countryside.
