How to Kill a Tree

Physical and Chemical Methods

Eastern white pine tree.
David Beaulieu

Trees lavish so many benefits on a property and its inhabitants that the very suggestion someone might wish to kill a tree is likely to elicit gasps of disbelief. In addition to their beauty, trees can function as living privacy fences and noise barriers. They can furnish shade both for you and for your shade garden. Trees not only provide a home to wildlife but also offer "cover" that will make wild birds feel safe enough to visit your bird feeder and spend enough time there for bird watchers to thoroughly admire their colorful plumage and delightful antics. It is hard for some gardeners to imagine why anyone would ever wish to kill a tree.

Reasons for Killing a Tree

And yet, while many homeowners welcome the presence of trees on their properties, not all do. Moreover, even homeowners who, generally speaking, find trees beneficial sometimes have a good reason why a particular tree just has to go. These reasons include that a tree can:

  • Pose a danger to your house, garage, shed, etc.
  • Pose a danger to a vehicle parked in a driveway
  • Pose a danger to people, buildings, or vehicles on a neighboring property
  • Put out roots that threaten a septic system, etc.
  • Be an invasive species
  • Cast shade on a portion of your land needed for growing plants that require full sun
  • Put out a flower whose pollen gives you an allergic reaction
  • Be susceptible to diseases and/or pests that you do not want to deal with
  • Make a mess in the yard that lovers of low-maintenance landscaping will despise having to pick up
  • Take up an unacceptably large amount of space on a small property
  • Begin to crowd another tree that is more highly valued

How to Kill a Tree

There are two broad categories of techniques for killing trees: physical methods and chemical methods (poisoning). Some homeowners will want to avoid the chemical methods, whether simply on principle or because they have safety concerns regarding the use of chemical herbicides (as when, for example, the tree to be killed is adjacent to a vegetable garden). Choose from the following methods to kill a tree after assessing your own personal preferences and landscaping needs:

Cut the Tree Down

The most popular physical way to kill a tree is to cut it down. However, if the tree to be removed is a large tree, then, especially if it is located near anything important that it could damage (such as your home, a neighbor's home, telephone wires, etc.), do not undertake the task yourself. Hire a professional to remove the tree. If your reason for removing the tree is to create extra space in a small yard, you will also want to get rid of the stump.

Girdle the Tree

Girdling is another physical method that sometimes (but not always) works to kill a tree. The girdling technique takes advantage of the fact that nutrients and water travel up the tree using its bark as a "highway." The idea is that if you remove a band of bark around the trunk's circumference, you can deprive the tree of enough nutrients and water to kill it. To girdle a tree, you will need to penetrate the bark to a depth of about 1.5 inches to 2 inches with an ax. The width of the band will vary depending on the size of the tree but should be at least 2 inches on even the smallest of trees.

One problem with the girdling and chemical methods for killing trees is that, in some cases, they do not go far enough. For example, if you need to get rid of a large tree because it poses a danger to your house, you will still need to remove it afterward because even the branches of a dead tree can damage a house if they fall on it. But if you are getting rid of a tree because it puts out a messy fruit and you just want to stop it from fruiting, it may be perfectly acceptable to you to kill the tree by girdling it and leave the dead tree in place.

Inject Poison Into the Tree to Kill It

You can also buy specialized equipment used to inject herbicide directly into the tree to kill it. Injection points should be every 2 to 6 inches around the circumference of the tree, about 5 feet up from ground level. Penetrate the tree 1.5 to 2 inches deep. This method is efficient, but the downside is that the equipment can be relatively expensive to purchase. To avoid this extra cost, an alternative to the injection method is to create the holes using a drill, then squirt your herbicide into the holes.