Can You Use Old Motor Oil to Fertilize Your Lawn?

There’s a chance that you may have heard about people using old motor oil as fertilizer for their grass and have been wondering if this is, in fact, a viable and beneficial option. Unfortunately, this is nothing more than a myth—motor oil will provide nothing good for your grass and will most likely harm it.

The notion that pouring motor oil on your lawn will help fertilize it most likely comes from the practice that oil refining companies would use to dispose of waste oils.

They would be drilled into the soil’s surface, which would later get fertilized and plowed, and the microorganisms in the soil would then digest the waste. This practice was not used to enhance the soil in any way; it was only used to dispose of waste.

Just pouring used motor oil onto your grass will only harm it, not to mention that it’ll also pollute the water supply. Motor oil is sticky, insoluble, and sometimes contains toxic chemicals, so it shouldn’t be a big surprise that it’ll only bring harm to plants.

Dumping used motor oil on the ground or down a drain could possibly pollute millions of gallons of fresh water, and that’s from just one oil change. There’s nothing but negatives to come from pouring used oil onto your grass.

Alternative Fertilizer Options

Just because you can’t use motor oil to fertilize your lawn doesn’t mean there aren’t better alternatives. There are many options on the market that will do a great job at fertilizing your grass—and are designed to do just that too.

Most fertilizers contain a combination of phosphorus, nitrogen, and potassium. There are also organic options such as composted manure, blood meal, and kelp. Either way, whichever option you choose will be much better than using motor oil.

What Will Happen if You Pour Motor Oil on Your Grass

To start, pouring used motor oil on your lawn will kill the roots of any plants it comes in contact with. While this in itself may not seem like a bad thing if you have weeds, it’ll also kill all the desirable plants too.

On top of this, the chemicals from the oil will leach into the water table and pollute it, which is especially bad if well water is used in the area. If near a lake or pond, it could also harm the wildlife that resides there.

If polluting the water in your area and killing all your plants isn’t deterring enough, you could also face fines, as improperly dumping oil is illegal. There are many safe ways to dispose of used and unwanted oil, and it’s always worth it to do the responsible thing and dispose of it properly.


As intriguing as it may sound to pour motor oil on your lawn, this will do nothing to help it grow and will only end up killing it. It’s best to find alternate fertilizer options and dispose of your used oil elsewhere—your grass will thank you for it.

Also read

Killing Tree Stumps With Motor Oil

Does Diesel Killl Weeds

Someone Drove on My Lawn! What To Do With Your Grass

Lawn Mowing Etiquette – Be a good neighbour

What is the effect of Dish Soap on Lawns – is it Safe to Use?

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