Roundup, or Glyphosate, is a herbicide used by a wide range of consumers and professionals alike. The availability of the product and typically good results have combined to make Roundup a herbicide of choice in many applications. Roundup is effective on a wide variety of grasses and weeds, however, it is also effective when used to kill unwanted or damaged trees.
Determine the tree to be killed using Roundup. Carefully consider whether or not to eradicate the tree, including the final removal of the tree and other considerations such as increased light, etc.
Check with local sources such as Agriculture Extension Offices regarding the use of herbicides to kill unwanted trees. The office may be able to offer insight or suggestions to aid in the process.
Implement one of three methods regarding the application of Roundup to the tree. There are essentially three effective methods which allow the Roundup to reach the growing tissue of the tree. This is necessary for the herbicide to spread throughout the trunk and kill the tree. These methods include cutting a wedge into the trunk using an axe, drilling holes in the trunk and removing a section of bark from the tree trunk.
Using a measuring cup, follow the manufacturer's directions for properly mixing a high concentration of the herbicide which will be sufficient to kill the tree. Empty the herbicide into a spray tank and add the recommended amount of water to the tank following the manufacturer's directions.
Use an axe to form several wedge-shaped cuts in the trunk of the tree. The wedges should be at a downward angle. The purpose is to allow the Roundup to be poured and held in the wedge so it may be absorbed by the tissue of the tree. The drill method involves several holes of at least 3/4" diameter drilled around the trunk at an angle. The final method requires a one-foot-wide section of the bark to be removed. In all of these methods, apply the Roundup to fill the wedges or holes, or completely saturate the exposed trunk.