Roundup quickly exterminates vegetation it comes into contact with. However, is it safe to apply Roundup near trees without harming them?

As a broad-range non-selective herbicide, roundup kills trees, shrubs, weeds, and all plants it comes into contact with. Spraying roundup near a tree will not destroy the tree. To kill it, you must spray it on the leaves, roots, and foliage. However, using a roundup near a tree several times may kill it, especially if the tree is young or just a seedling.

Selective use of roundup is necessary for landscapers and arborists.

Will spraying roundup near your trees kill them

How roundup works

Roundup is an all-around herbicide. It kills a variety of plants and trees of different sizes. Glyphosate1 is the main component of roundup. When it is sprayed on the plants, it is absorbed by the leaves, and transported to the roots where it inhibits the uptake of nutrients from the soil causing the plant to die.

The impact of roundup is first seen when the leaves turn brown and dry. The foliage starts to fall and eventually, the plant or tree dies. The plant dies around two weeks after the herbicide is sprayed on the plant.

Will roundup kill a tree?

Spraying roundup on the foliage of a young tree can kill it easily. However, it will not affect a mature tree.

To kill a mature tree with roundup, it must be injected into the vascular system. Consequently, it will get to the roots of the tree, prevent nutrient absorption and kill it. Also, spraying roundup on tree suckers can kill the tree as the suckers are connected to the vascular system.

Will roundup kill a tree stump?

To kill a tree stump with roundup, you have to inject it into it. However, it is more effective when sprayed on the leaves.

Applying roundup to the bark of a mature tree will not kill it.

How do you use roundup on weeds without killing trees?

If you will be spraying roundup on weeds, here are some tips to ensure it does not get onto the leaves and foliage of unintended trees or plants.

  • Use roundup on a calm and hot day. On windy days, the wind may spread the herbicide onto other plants’ leaves.
  • Reduce pressure on your sprayer and aim it directly at the leaves and foliage of the intended plant.
  • Follow manufacturer guidelines on how to mix the concentrate with water to avoid destroying the soil in your garden.
  • Use a protective barrier for young trees and plants that you do not want to be killed by the roundup. You can cover them with paper or a metal sheet.
  • Use a garden hoe or remove shallow-rooted weeds by hand if they are close to trees and other plants you want to preserve.

If you accidentally spray roundup2 on a tree, you can prevent the tree from absorbing it by pouring water around the tree. It dilutes the concentration of roundup and minimizes its effect on the tree.

How to kill a tree with roundup

  1. Ensure to pick the right tree that you want to kill with roundup. Cover up the rest of the trees. Protect the juvenile trees and saplings that will die as soon as they are in contact with the herbicide. Also, ensure that there aren’t other plants near the tree that you do not want to kill.
  2. Check with local agriculture offices on the use of roundups. It is banned in some jurisdictions. Additionally, they are likely to provide more information on how to use it more safely. If you are allowed to use it, go ahead.
  3. Apply roundup to the tree. You can bore holes in the trunk and inject it into the tree. Alternatively, you can cut a section of the bark with an ax a few inches into the trunk and apply roundup to the tree. Applying it to the vascular system of the tree is the only way to use it effectively. Otherwise, the tree will not die.
  4. Check for the manufacturer’s instructions on how many roundups you need to inject or pour into the trunk to kill the tree. Pour it into a cup and then into the tree carefully. It takes 10-14 days for the effect of roundup to be visible. The tree’s leaves will turn yellow, they will then dry, and eventually, the tree will die.

If you want to kill a tree with a roundup, follow the instructions above. If you cannot do it alone, hiring a pro is best.

Pros have the tools and knowledge on how to best use roundup to kill a tree. They will save you time and injuries.

  1. U.S. Environmental Protection Agency, (2023) Glyphosate. <> Accessed: 16-02-2024.
  2. Penn State Extension, (2022) Use Glyphosate With Care Near Trees! <> Accessed: 16-02-2024.
Ben McInerney
Author: Ben McInerney - Ben is a qualified arborist with 15 plus years of industry experience in Arboriculture. He ran a successful tree service before turning to writing and publishing. Ben is dedicated to providing users with the most accurate up-to-date information on everything trees.