Sumo Gardener

Will Roundup Kill Trees? Is It True?

Spring is upon us, and it is time to start preparing your yard for the beautiful summertime. Undoubtedly, you are going to end up facing strong, overpowering weeds that take over your grass.

Weeds are invasive, and you will need to find a way to take them down. You’ll wonder will roundup kill trees.

It is important to know the truth, especially if you have some lovely, decorative trees in your front yard.


What is Roundup?

What is roundup

To best answer the question, you have to know how Roundup works. Glyphosate is the main, active ingredient that is absorbed through the leaves into the roots.

Considered a broad-spectrum herbicide, glyphosate is an organic, high-phosphate compound, typically diluted in liquids then sprayed onto the foliage. Once absorbed into the plant, it stops the plant’s ability to make amino acids.

The bad thing about glyphosate is that it is non-selective, so it kills any plant it touches. It is important for users to not overspray and to minimize drifting.

After absorbing into the soil, glyphosate stays in the ground for up to six months. This is why so many people use it for a long-term solution for weeds.

Reaching Tree Roots

Reaching Tree Roots

As mentioned earlier, Roundup can stay in your soil for a number of months. The roots of surrounding plants can absorb the glyphosate.

If you happen to spray Roundup near or the wind pushes it to the tree, there is a possibility that the tree roots can suck up some of the glyphosates.

Trees could also absorb the Roundup from the roots of the surrounding, dying plants. If trees were to take in some of the Roundup, there is a possibility that it could significantly damage the health of the tree.

The tree will have issues finding all of the essential micronutrients needed for survival, such as iron, boron, manganese, and zinc. While there is a chance that Roundup will kill the tree, there is also another possibility – diseases.

A tree that absorbs Roundup could develop one or more fungal diseases. Root rot, wilt, rust, and Anthracnose are all options that could produce, potentially damaging the tree forever if it survives.

Hardwood trees, like ash, birch, elm, and hickory, are more prone to the fungal diseases, Anthracnose.

Other Forms of Damage by Roundup

There are even more types of damage that can be caused by exposure to Roundup. Glyphosate is known to reduce the cold hardiness of trees.

They lose their ability to survive long dry spells. Unlike fungal diseases, these effects can last for a long time, potentially causing significant damage or death if facing a frigid winter. Gardeners should avoid the use of Roundup near fruit-bearing trees.

If you use it around your apple trees to control weeds, the quality of the tree is affected. Harvested apples from these exposed trees tend to turn brown internally and spoil quicker than other apples.

Using Roundup to Kill Small Trees

Roundup to Kill Small Trees

Perhaps, you are aiming to kill a small tree, brush, or bushes with the use of Roundup. If this is your purpose, Roundup will kill trees if you use the proper concentration as designated on the label.

The level will vary based on the type of tree you are trying to kill. However, 1 to 2 percent is a general recommendation when using a hand held sprayer.

It is best to apply the glyphosate during the mid to late summer. The tree is full of leaves. You want to spray all of the leaves heavily with the herbicide. It will take some time to cover the leaf area thoroughly.

This process works best only on small trees; it typically won’t kill a large tree. If done correctly, you should notice effects within seven to 14 days.

Drilling into a Mature Tree

Drilling into a Mature Tree

To kill a mature tree, you will need to drill into the side of the tree to inject Roundup. You should drill several holes around the base of the tree, reaching the growth layer of the tree.

However, it shouldn’t meet the center of the tree. Pour ½ ounce of glyphosate into each hole. It can take one to six weeks for the tree to die, so long as you apply it during the active growth period of the late spring into early summer.

Will Roundup Kill Trees?

There are multiple answers to this question! If you are spraying weeds near your tree and some happen to drift over, it shouldn’t kill your tree if it is a large, mature one.

You can use Roundup to kill small trees and bushes when applied as the directions indicate. You could also use Roundup to kill mature trees by drilling holes into the tree and pouring large amounts directly into the tree.

Luckily, it takes more than a few sprays touching your lovely, huge Oak tree to kill a mature tree.

About the Author Ann Katelyn

I'm Ann Katelyn, Creator and Chief Author of Sumo Gardener. Since I was a child I've always been fascinated with plants and gardens, and as an adult this has developed into my most loved hobby. I have dedicated most of my life to gardening and started Sumo Gardener as a way to express my knowledge about gardening with the hope of helping other people's gardens thrive.

follow me on:

Leave a Comment: