All you need is a little herbicide and elbow grease
Trees provide a lot of benefits, from shade and oxygen to the lime for your margarita. But there are still reasons you might need to know how to kill a tree—even if it’s healthy.
Trees can grow dangerously close to your foundation, for example, or you might be dealing with an invasive tree species that will slowly take over your yard. Whatever the reason, these 10 tips will show you how to kill a tree and its roots.
Not sure whether you should remove a tree from your yard? Hire a professional arborist to inspect the tree and help you determine if you should take the next steps to cut it down.
One of the best ways to kill a tree is to simply cut it down. This works best with certain tree species that won’t regrow (like oak, pine, palm, or maple). With other species, you’ll also need to treat the trunk or kill the roots.
With this method, the bigger the tree, the bigger the job. If you don’t have experience using a chainsaw, you might be able to find someone to cut your tree down for free. It depends on your city, the health of the tree, and where it’s located. If that’s not an option, call a tree removal service near you to ensure this project is done properly and safely.
Once you cut down your tree, you need to make sure it won’t grow back. Some species—like elm, dogwood, and ficus—are resilient. A simple chopping job isn’t enough. In this case, you can grind or treat the stump.
The cost of professional stump grinding is typically $170 to $500. If you want to go the DIY route, spray the cut surface with tree killer herbicide. You’ll only need to treat the outer 3 inches if it’s a larger tree, since the internal heartwood is already dead.
Salt is a good alternative to herbicide, but it’s best used to kill tree stumps by dehydrating them so they can’t re-sprout. First, you’ll need to cut down your tree. Then, you can drill holes in the stump and fill them with rock salt or Epsom salt.
Wet the salt, sprinkle a ring of salt around the base, then cover the stump with a tarp to make sure the salt won’t wash away in the rain. Keep in mind that salt will kill nearby grass and vegetation, so use this method carefully.
Girdling is the process of removing the bark around the circumference of the tree. This essentially starves the tree because it can’t transport nutrients.
To girdle the tree you want to kill, use a hatchet to remove all layers of bark in a circle around the trunk. The line of your ring should be anywhere from 2 inches wide (for a small tree) to 8 inches wide (for a large tree).
If you’re wondering how to poison a tree effectively, it all starts with a cut. Cutting through the surface of the bark creates a direct pathway for herbicide to enter the tree’s vascular system.
Start by trimming your tree as much as possible, then use an ax or hatchet to make downward cuts in the bark. Immediately spray a tree-killing herbicide into the fresh cuts. This method works best outside the growing season, where sap might offer some protection.
Certain chemicals for tree-killing, called basal bark treatments, are specifically designed for use on the bark of woody vegetation. To kill a tree, spray this type of herbicide on the bottom 12 to 18 inches of the tree trunk from spring to fall.
Though this method doesn’t pose a huge risk to other vegetation, it’s still best to hire a tree service in your area to make sure it’s done safely.
As far as DIY methods go, some people try killing a tree with bleach. This isn’t really effective because it will only kill the foliage it touches. It won’t kill the actual plant unless it’s a sapling or a delicate ornamental tree.
Instead, between early summer and early fall, use an herbicide on foliage up to 15 feet high. The treatment isn’t as effective when trees are heat- or drought-stressed, so make sure temperatures are cooler, and your trees are well-watered.
Soil treatments can be highly effective because they focus on killing the roots of trees. Without healthy roots, a tree essentially starves. Choose a tree root killer that’s meant for soil and not one made to pour into your pipes (those are for tree roots that clog plumbing). Once you have the soil treatment, apply it per the manufacturer's instructions.
Trees and other vegetation can actually meld together in a process called root grafting. This means that whatever you spray on the tree you want to kill could end up inside the grafted plant.
Typically, this only happens among the same species or those in the same genus, but it’s still important to be mindful since tree roots can stretch a distance equal to the height of your tree.
If you’re using herbicides, keep it safe by calling a professional. You may face local regulations, so at the very least, call your local environmental agency to check.
Do copper nails kill a tree? The short answer is maybe. Before you head to your toolbox, know that this method isn’t backed by science. The truth is that hammering in a few copper nails won’t do much to a healthy, mature tree, according to the Invasive Species Network.
Theoretically, it could kill a small sapling, but there are far more effective ways to get rid of those too. It’s best to skip this method and focus on something you know will work.
While the fastest way to kill a tree is to simply cut it down, there are several other methods to choose from. You should hire a professional tree removal service to cut down a tree to ensure your personal and property safety. Some slower but effective options include treating or grinding the tree stump or using a basal bark treatment.
In nature, there are many things that can cause a tree to die, including diseases, insects, and natural disasters such as fires or droughts. Non-natural methods of killing a tree include herbicides or manual intervention, such as cutting it down. Consult a tree removal professional about your options for naturally killing a tree.
Bleach can potentially kill some types of delicate ornamental trees, but for the most part, it will only kill the foliage it comes in contact with. Applying bleach is not an effective method of killing a tree. A better option is to use an herbicide, which is a chemical compound designed to effectively kill a tree.
