What is Roundup and is It Effective on Palm Trees?

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Roundup is one of the most popular herbicides for controlling unwanted plants and weeds. Its main active ingredient is Glyphosate, and it is effective on a wide variety of plants. but is it effective to kill Palm trees?

Roundup can kill small Palm trees by spraying the foliage of the tree with it. For mature trees, Roundup needs to be applied directly to the cambium layer of the Palm tree. This can be achieved by removing or damaging the bark or the tree and applying Roundup directly to the exposed area.

Let’s take a look at whether you can use Roundup on Palm trees and how to use the herbicide correctly for the best results.

What Is Roundup?

Roundup is one of the most commonly used weed and plant killers used in the US today. The main ingredient in this herbicide is Glyphosate. This herbicide has been used by everyone including professional farmers, gardeners, or a biologist trying to control invasive plant varieties.

Roundup is very efficient at killing small to medium-sized trees, its effects can be seen within the first few hours and the tree can die within a couple of weeks after application.

How Does It Work?

Roundup is systemic in nature, this means that it will be absorbed by the tree, and using the tree’s vascular system, it travels to leaves and down to trees roots.

After absorption, Roundup will start targeting and inhibiting a specific enzyme within the plant called EPSP Synthase. This enzyme is responsible for regulating the production of essential proteins which a plant needs for growth.

The first sign of Roundup working on a plant can be seen through the yellowing of its leaves and foliage. The plant will slowly die over the course of a couple of weeks.

Will Roundup Be Able to Kill Palm Trees?

Roundup or Glyphosate is not the preferred herbicide to be used on Palm Trees. This chemical is most effective when it is sprayed directly on the leaves and the foliage of the tree. Most of the Palm Species don’t have a lot of foliage cover, a large part of the tree consists of a woody trunk which is not as efficient in absorbing Glyphosate.

If you have to kill a smaller palm tree where the foliage can be sprayed with Roundup directly, then the herbicide will kill the Palm tree.

The best way to apply Roundup would be through cutting down the tree and treating the stump with the herbicide. Alternatively, you can also use Cut surface treatment or Chemical Injection Method. The latter involves drilling holes into the trunk of the tree and spraying the herbicide into these holes.

In short, Roundup can be used to kill Palm trees, but it needs to be applied directly to the cambium layer of the tree. This can be done by cutting gashes into the bark or drilling holes into the trunk of the Palm tree. Applying Roundup directly on bark will not affect the tree enough to kill it.

Can I spray Roundup Around the Palm Tree to Kill it?

Spraying Roundup on the soil near the base of the tree can work but this won’t be as effective, and it doesn’t guarantee that the tree will die. People have reported cases where using Roundup around trees has killed the tree, but generally, it does not stay active in the soil for very long.

Roundup loses its effectiveness in the soil relatively quickly, and you will have to repeatedly spray it on the soil before the tree absorbs enough of it.

On the other hand, spraying too much herbicide on the soil will affect the soil quality and vegetation in the area.

What Are the Best Herbicides for Killing Palm Trees?

Herbicides which have Triclopyr as the main ingredient are most effective on Palm Trees. For example, Garlon 4 Ultra, Relegate, Forestry Garlon XRT, Aligare Trycloper are good choices, but not available for the consumer market.

However, I can Recommend Trycloper 4 from Amazon. (Affiliate link)

You can read more about How To Kill A Palm Tree here

What Equipment Will You Need to Apply Roundup?

To effectively use Roundup, you will need the herbicide along with an effective delivery method. If you only have to kill a few small trees or shrubs, then you should use a comfort wand. It is a small, portable spraying device that will give you a continuous herbicide spray without any of the heavy equipment.

How to Use Roundup Correctly?

Roundup doesn’t need to be mixed with anything and it can be used straight out of the container.

  1. Carry out the process in nice calm weather to make sure the herbicide does not get carried away.
  2. Fill the sprayer with the herbicide and spray it on the foliage of the plant you want to kill.
  3. Make sure all the leaves are covered by the herbicide and that it dries properly.
  4. After the first layer has been absorbed, repeat the spraying process.

Once you spray the herbicide on the plant, within 30 minutes it will be absorbed by the plant. After this, you don’t have to worry about it washing away due to rain or water.

More methods on how to kill a Palm tree

How Long Does Roundup Stay Active in The Soil?

This topic has been a point of debate among researchers for quite some time. One study conducted by Cornell University states that the half-life of Glyphosate in the soil is between a few days to 174 days.

This means that Roundup can affect soil for nearly 6 months. Some other studies point out that this half-life can be up to a year.

Most of the studies indicate that even though the chemical can be active for a long time, it becomes harmless to other vegetation rather quickly.

How Can You Protect Plants That Have Been Accidentally Exposed to Roundup?

If you have accidentally sprayed Roundup on plants or trees, no need to panic.

Wash the foliage or the area of the tree sprayed with water immediately. Roundup takes up to 30 minutes to be absorbed, before that it is susceptible to water and can be washed away.

If the Roundup was applied to the soil accidentally, you can also water the soil to dilute the chemical’s concentration. Another alternative is to use dirt, ammonia, or bleach to neutralize the chemical.

Frequently Asked Questions

What to do after the tree is dead?

Once the tree is dead, it has to be cut down. Otherwise, it will eventually dry out and fall down anyway, creating a potential hazard depending on the location of the tree.

Once the tree has been cut down, what to do with the remaining Palm stump?

Once The tree has been cut down, you can wait for it naturally compose, or remove the Palm stump yourself, using a grinder or chemicals to speed up the rotting process.


Although Roundup or Glyphosate works on most plant varieties, it is not the most efficient to apply directly on mature Palm Trees. The most efficient way of using this herbicide is through spraying it directly on the Palm’s leaves if the tree is small. Alternatively, you can also cut the tree down and treat its stump with Roundup or drill holes into the trunk of the tree and apply the herbicide into the cambium layer.

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