How to Drill Holes & Put Herbicide Into Trees to Kill Them

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Things You'll Need

  • Safety glasses

  • Drill

  • 10-mm drill bit

  • Herbicide containing glyphosate

  • Garden sprayer

  • Water

  • Spray paint

Drill holes in tree trunks for better herbicide penetration.

Although many trees are desirable in the home landscape, some are not. Whether you have an invasive species or simply don't like a tree variety, there are ways to kill it. One way to kill the tree is by drilling holes into the trunk, into which you then inject a powerful herbicide solution. The holes push the herbicide further into the trunk, where the foliar system transports it down to the roots, thus killing the tree.


Drilling the Holes

Step 1

Insert a 10-mm drill bit into a drill and don safety glasses.

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Step 2

Place the drill bit against the tree trunk, approximately 12 inches from the ground and positioned at a 45-degree angle, pointed downward. Squeeze the trigger to create a hole. The depth of the hole should range from 1/2 inch to 1 1/2 inches deep, depending on the diameter of the tree trunk. Do not extend the hole all the way through the trunk.


Step 3

Repeat the process on the opposite side of the trunk to create another hole.

Step 4

Move down the trunk by approximately 2 inches and create two more holes on either side of the trunk just as you did with the first set of holes.


Step 5

If the tree has multiple trunks, repeat the process on the other trunks as well.

Injecting the Herbicide

Step 1

Fill a garden sprayer with a herbicide containing the active ingredient glyphosate. Use the amount of solution specified on the herbicide bottle.


Step 2

Dilute the herbicide with water by adding five parts of water for every one part of herbicide. Close the sprayer up and shake it gently to mix it.

Step 3

Hold the nozzle of the sprayer 1/2 inch away from the tree trunk holes and fill them completely with the mixture. Use care as you do so not to splash the herbicide back on yourself.

Step 4

Spray-paint a small X or dot on the tree so you can identify it later.


Trees that are drilled before injecting herbicide typically begin to die in six weeks, with the process being complete by six months.

All trees that have a trunk diameter of 5/8 inch or more can successfully be killed using the drilling method.



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