Tordon is one of the best tree-killing herbicides on the market. By making cuts in a tree’s bark and treating the cuts with Tordon, the chemical will kill even large trees in a matter of weeks. Alternatively, you can kill smaller trees and brush by spraying their leaves with Crossbow, a powerful brush-killing herbicide. Other options include spraying the bottom 12 inches (30 cm) of bark with Triclopyr-based herbicide or injecting concentrated Roundup into holes drilled in the tree trunk.
What is the Best Chemical to Kill a Large Tree?
The most effective herbicide for killing large trees is Tordon. Most other chemical herbicides are designed to kill small trees and brush, but Tordon can kill larger trees than its competitors. The most effective method for using Tordon to kill trees is to use it as a cut-surface treatment. This means it should be applied to cuts in the bark or holes drilled into a tree. It’s one of our top choices for killing trees without cutting them down.
- This Tordon tree killer is the best product for killing large trees.
- Apply Tordon to cuts or holes made in tree bark to kill large trees.
- Paint Tordon on cut stumps to kill tree roots and prevent unwanted trees from growing back.
In addition to killing large trees, Tordon is also the best product for treating stumps to make sure the tree does not grow back. Within 30 minutes of cutting down a tree, paint Tordon in a ring along the top of the cut tree stump. The herbicide will work down to the tree roots, killing them. This prevents unwanted trees from sending up new plants from the roots.
- Effectively kills stumps with superior results.
- Easy-to-Use blue dye helps you keep track of stump treatment.
- Perfect for both in-season and off-season brush control.
4 Ways to Kill a Tree With Chemicals
Tree removal can be a difficult process. Systemic herbicides help to decrease this work by killing trees quickly. Trees and brush are often much easier to remove once they’re dead. Here are the best methods and products for killing trees quickly with herbicide:
Cut-Bark Method
Nothing beats the cut-bark method for quickly and easily killing a wide range of trees. For this method, all you need is a hatchet and a bottle of Tordon tree killer. You can use this method to get rid of nearly any type of tree. Just follow these steps:
- Pick a point between ankle-height and waist-height on the tree.
- Use your hatchet to make a downward angled cut through the bark.
- After making the cut, the bark you cut should be sticking out from the tree in a ‘V’ shape.
- The cut should be deep enough to reveal the white sapwood beneath the bark.
- Repeat this process to make cuts every 2–3 inches (5–7.5 cm) around the circumference of the tree trunk.
- Pour Tordon into each of the gashes made in the tree bark.
- Allow 1–2 weeks for the tree to die.
By following this simple system and pouring Tordon into cuts in tree bark, the herbicide will be transported through the entire tree. In a matter of weeks, the entire tree will be killed, including the roots. This system works best in fall when the tree is transporting nutrients down to the roots, but Tordon and cut bark treatments can kill mature trees at any time of year.
Foliar Spray
If your tree is 15 feet tall (4.5 meters) or smaller in size, you can kill it by spraying systemic herbicides on the leaves. The best product to use for this method is Crossbow. It is a systemic plant killer that enters through the leaves and is carried to the roots by the plants’ vascular system. Crossbow is designed to kill tough brush and woody plants, so it’s more effective than competitor products, such as Roundup.
- Trees smaller than 15 feet tall (4.5 meters) can be killed by spraying a systemic herbicide on their leaves.
- This Crossbow herbicide is the best product for killing small trees and brush quickly.
- Crossbow kills trees to the root in 1–3 weeks.
If you are spraying the leaves of a tree to kill it, make sure to spray on a wind-free day. This will prevent the spray from being carried to nearby trees and plants. Also, do not try to spray the leaves of very tall trees. Trees that have grown more than 15 feet tall (4.5 meters) are likely to survive this treatment.
- Size: 1 Quart.
- Contains 2-4, D and Triclopyr for control on most unwanted trees and brush.
- You can use this on non-crop and non-timber areas.
Basal Bark Treatment
If you are killing a tree that is 6 inches (15 cm) or smaller in diameter, you can simply spray the bark at the base of the trunk with the correct herbicide. For this system, use an ester formulation of Triclopyr, called Garlon 4. This herbicide must then be mixed with a bark oil. By combining these products you will create a spray that soaks through the bark to kill the tree within 1–3 weeks.
- Trees 6 inches in diameter (15 cm) or smaller can be killed by spraying a mix of chemical herbicide and bark oil on the base of the tree.
- Use this ester formulation of Triclopyr, called Garlon 4.
- Mix 20 ounces (2.5 cups or 600 ml) of Garlon 4 with 1 gallon (3.75 liters) of this bark oil in a pump sprayer.
- Spray the mix onto the bottom 12 inches (30 cm) of bark all the way around the tree.
- The tree will die within 1–2 weeks.
Basal bark applications are a great choice for clearing small trees and brush from areas. Because it doesn’t require you to cut the tree bark and you don’t have to spray the leaves, this is a very easy and effective treatment. It will wipe out small trees quickly, but isn’t very effective at killing large trees.
Injection Method
You can kill trees with a concentrated form of Roundup by drilling holes in the tree, then filling them with Roundup. Glyphosate, the active ingredient in Roundup, is capable of killing trees when it is used in its undiluted, concentrated form. Here’s how it’s done:
- Equip an electric drill with a ½-inch (12 mm) drill bit.
- Drill a hole into the tree trunk to a depth of 1.5 inches (4 cm).
- Angle the hole downward at 45 degrees.
- Repeat this process in a ring around the tree, drilling one hole every 2–3 inches (5–7.5 cm).
- Pour this concentrated Roundup into each hole.
- Allow 1–3 weeks for the tree to die.
This process is very similar to the cut-bark method described above. In fact, you can use Tordon and concentrated Roundup interchangeably for these two methods. We typically prefer to use Tordon because it contains a blue dye that allows you to easily spot which trees and cuts have been treated with herbicide.
- Easy application and rainproof within 30 minutes.
- Noticeable results with weeds wilting and dying within 2-4 days.
- Kills a large variety of unwanted and invasive weeds and grasses.
What Chemical Can Be Used to Kill Trees?
The best chemicals for killing trees are:
- Tordon: Can be used to kill large or small trees when it is applied to gashes or holes in tree bark.
- Crossbow: Kills trees up to 15 feet tall (4.5 meters) when it is sprayed on leaves.
- Triclopyr: When an ester formulation of Triclopyr is mixed with bark oil, it can be sprayed on the base of small-to-medium trees to kill them.
- Roundup Concentrate: Roundup and other Glyphosate concentrates that contain 40–50% Glyphosate can be used to kill trees of any size. Like Tordon, it must be applied to cuts or holes in tree bark.
These 4 chemicals are the best way to kill trees permanently, including the tree roots. Depending on the size of the tree or the number of trees you’re killing, select a different method. Tordon or concentrated Roundup is a must for killing large trees. Crossbow is great for killing trees that are small enough that you can easily spray the leaves. Patches of small trees and brush are quickly wiped out by spraying a Triclopyr blend on the bottom 12 inches (30 cm) of tree bark.