How to Add Motor Oil to a Weed Killer

Weeds are unsightly, hard to kill and just plain stubborn most of the time. Weed killer can be expensive and pulling the weeds by hand is hard on the back and knees. Many people do not know this, but you can actually use your old, used motor oil as a very effective weed killer. Motor oil will kill any weed it comes in contact with, but will also kill any grass, plant or flower that it touches, so it needs to be used with care.

Step 1

Remove your used motor oil either out of your car or out of the can where you are storing it and pour it into the pump sprayer. Do not fill it all the way, as the oil is much thicker than what the sprayer is meant for.

Step 2

Locate your weeds that need to be disposed of and section them off from the other plants, flowers or grasses that you would like to keep alive. Use a clear plastic tarp to cover the plants you want to keep, as this will allow sunlight to still penetrate to the plants.

Step 3

Use one spray of the motor oil per weed. You do not need a lot of the motor oil on each weed. Whatever the oil touches, it will kill, so be careful not to spill or over spray onto any other greens.

Step 4

Wait up to 48 hours for the weed to be completely killed and remove it completely.