Methods To Kill A Tree Stump Using Motor Oil?

  • By: CarlBroadbent
  • Time to read: 7 min.
Affiliate Disclaimer

As an Amazon Associate I earn from qualifying purchases. So, thank you for using the links.

There are different methods you can use to kill a tree stump. If you don’t kill it, the roots will continue thriving, interfering with structures, buildings, or even pathways.

Also, the natural decomposition of a tree stump can take many years to complete depending on the wood density.

Tree stump
Used motor oil best for getting rid of tree stump

The use of grinders can be pretty expensive, and blowing up the stump is too dangerous.

One of the best ways to keep tree stumps at home is to directly pour motor oil on the roots. You can also burn up the tree stump using motor oil.

Key Takeaway – This method is considered one of the best as motor oil is readily available and is cheap. When used correctly, it is considered more environmentally friendly than the use of other chemicals. 

How To Kill A Tree Stump Using Motor Oil?

Pouring motor oil to the heart of the tree stump

You can kill a tree stump with motor oil by pouring it at the heart of the stump.

The oil breaks down cellulose and lignin. This blocks the vascular systems preventing water running from the roots to the tree stump.

Nonetheless, this method can block natural decomposers from breaking down the stump.

Decomposers like fungi are responsible for breaking down organic matter.

What steps should I follow to kill a tree stump using motor oil?

Drilling holes in tree stump
Drilling holes tree stump
  • Drill angled holes facing downward around the base of the tree stump and from the stump. The holes should be two to three inches deep. Make sure the drill matches the size of the oil drip system or the syringe.
  • If the tree stump roots are visible, take advantage of them and drill holes on them, too. This is because the roots are responsible for absorbing nutrients and water, which can initiate regrowth.
  • Pour the oil into the drilled holes using a funnel or an oil drip system. Once the oil is absorbed, pour more to increase efficiency. Most people recommend burning the tree once the tree stump has absorbed enough oil. This method can work well also but you will have to be more careful.

How long does it take for motor oil to kill a tree stump?

The use of motor oil is time-consuming, and you have to be patient with the process.

If you want to speed up the process, you can pour gasoline. Pouring gasoline will kill it within six months.

However, it depends on the size of the tree and many other factors. If you want to speed up the process, you can kill the tree stumps by burning them.

Burning the tree stump using motor oil

Motor oil is flammable, and you can use it to burn a tree stump.

Burn the tree stump
Burn the tree stump using motor oil

Using a drill with one inch bit, drill forty-five-degree angle holes around the tree stump.

Pour two spoons of the motor oil into each hole using a funnel. Place some kindle on the top and light the fire.

This method is much more effective than pouring the motor oil on the drilled holes. This is because it is way much faster than the first one.

What steps should I follow when burning a tree stump using motor oil?

Tree stump and motor oil
Get rid of a tree stump using motor oil
  • Gather the materials you need during the process. You will need a long one-inch bit drill to reach inside the tree stump. Choose a drill with high torque. You will also need a funnel, lighter, twigs and sticks, kindler, and motor oil.
  • At a forty-five-degree angle, drill even holes around the tree stump about four-inch intervals and three inches deep. Drill another hole on the top of the tree stump.
  • The total number of holes is based on the size of the tree stump. You will have to drill more than one hole for a large stump, while for a small tree stump, one hole is enough. 
  • Pour two to three tablespoons of motor oil in the holes using a funnel. Do the same around the drilled holes of the tree stump.
  • Place small twigs and sticks on the stump and add a kindler to start the fire.
  • Light the fire and step back to keep a safe distance to avoid injury.

What precautions should I consider while lighting the fire?

Don’t leave the fire unattended.

Ignorance could result in an enormous fire risking your home, plants, and vegetation.

Keep a few buckets of sand near or a fire extinguisher if the fire runs wild and uncontrollable.


Be Careful: Don’t use water to cool down the fire. Like other oils, dousing the fire using water can cause a fireball explosion which is very dangerous if you are too close. 


Can Used Motor Oil Kill Tree Stumps?

Used oil has many impurities collected from the running engine.

Huge Drill tree stump
Drill holes around the tree stump

However, you can use used motor oil to kill tree stumps. While this will take a longer time, you can use either of the mentioned methods.

This is a low-cost method of removing a tree stump.

If you have a car or a machine that uses motor oil, for example, a power saw, you can recycle the oil to save some money. 

What Are The Drawbacks Of Using Motor Oil To Kill A Tree Stump?

Even though motor oil is not proven to be the best and still poses some dangers and adverse effects, the method is demonstrated to work effectively provided you follow the correct procedure.

Killing Tree stump
Can used motor oil kill tree stumps?

Some of the drawbacks of using motor oil includes:

  • When you pour the oil, it will eventually end up on the ground. The next rain will wash the oil deeper in the ground reaching the water table where most people get their drinking water. Not only the people but other companies or other animals if they need water.
  • Some trees release toxic smoke when you burn them. The smoke will affect other living creatures and animals. You should be aware of the tree species you are working on.
  • Leaving the fire burning is harmful to the living things near the fire. The smoke can clog the leaves of other plants lacking space to expel waste oxygen that keeps them alive.
  • The motor oil will kill any vegetation it comes across when poured directly on the ground. It will kill the grass, plants, weeds, and even flowers on the ground.
  • For multiple tree stumps or large tree stumps, you must buy enough oil to kill the tree stump. The oil can be expensive, especially if you don’t have any used oil to recycle. Also, the job might cause a lot of damage to your farm due to using a lot of oil.
  • To work effectively, you will have to buy an oil drip system. This can be very expensive if you want to get rid of one tree stump. If you do not have an oil drip system, you will have difficulty getting as much oil as possible to the stump’s bark.
  • The use of motor oil can cause a great mess. Pouring the motor oil on the stump will give it a disgusting look

When Should I Call For Help?

Small tree stumps are easy to remove, but it can be pretty challenging for multiple stumps or a large stump in your compound.

As such you should seek professional assistance to do the job for you.

Additionally, fire can be scary to some people, and one might be afraid of controlling the fire.

Suppose you are poor with handling fires or find the job to be unattractive.  

If you have worked on the tree stumps for several months with no results, you can contact a professional to try alternative methods.

Final Thoughts                         

Most people use motor oil as a wood preservative since it is hydrophobic.

However, you can still use it to kill tree stumps. Applying motor oil on the roots or the tree stump itself is not enough to kill it.

But when poured into the most vital parts of the tree, the oil can kill the tree stump. 

You can also use the motor oil to burn the tree stump. This could be dangerous if you don’t follow the proper procedures or safety measures.

If you find it challenging to use motor oil, you can always seek help.

Also Read