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How to Burn Out Stumps With Phosphorus

tree stump image by green308 from

An old tree stump can be an unsightly and dangerous blemish on your property. Homeowners cut down trees for a variety of reasons, although stumps are often left behind. Mature tree roots can easily reach 10 to 15 feet underground, making them a challenge to remove. Powdered phosphorous can be used to burn out stumps and make them easier to remove. Phosphorous is a simple and affordable way to clear tree stumps from your property.

Drill a number of large holes in the top and sides of the stump with the auger bit. Ten to 15 holes are adequate for small stumps, with larger stumps requiring as many as 30 holes for proper phosphorous distribution. Auger bits are wide and allow the phosphorous to deeply penetrate the tree. If there are any exposed roots, drill two or three holes in each one to speed up the burning process.

Fill each hole with sodium phosphate powder. Sodium phosphate is a combination of salt and phosphoric acid and will heat up when water is applied, burning the inside of the tree stump. Wear gloves and a breathing mask to protect yourself while handling sodium phosphate.

Pour hot water over the stump and allow the phosphorous to work into the tree. Reapply the phosphorous four times, each application spaced seven days apart. Leave the stump undisturbed for a minimum of 30 days after the last application to give the phosphorous time to seep into the stump and loosen the roots from the soil.

Test the stump after 30 days by placing a crow bar under the stump and prying it out of the ground. If the tree stump moves easily, work your way around the stump, loosening each side with the crow bar and pulling it out of the ground. If the stump does not come out, repeat the phosphorous application and try again.


Straight phosphorous is highly dangerous and difficult to purchase. Sodium phosphate is much safer and can be purchased at most home and garden stores.


Seek immediate medical attention if the sodium phosphate powder comes in contact with your skin. It can cause severe burns if not properly removed.

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