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Why Is My Lawn Mower Spitting Out Grass – Top 8 Reasons Behind

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Are you a gardener who has recently bought a lawn mower for your garden? Has your lawn mower been malfunctioning recently? A malfunctioning lawn mower can be the pain of your existence, especially when you’ve spared precious time from your busy routine to attend to your garden.

Has your lawn mower been spitting grass out? Has your lawn mower, that has been spitting out grass been plaguing your thoughts? If so, you have found yourself at the right place because today we’ll be discussing the reasons behind why is my lawn mower spitting out grass.

Machines can’t always be relied upon, especially when you can’t know if they’ll work or not. This unpredictability is bearable on the days your lawn mower works fine but when it starts spitting grass out, it can get on your nerve. However, we need to realize there is a reason behind why is my lawn mower spitting out grass, so keep reading to find out!

Why Is My Lawn Mower Spitting Out Grass
Person Mowing Grass With Hand Powered Lawn Mower – via Flickr

Why Is My Lawnmower Spitting Out Grass?

The Grass Might Be Too Wet

This one is a little obvious because mowing wet grass is never a good idea. Truly, beware of the wet grass, as it can be the very reason why is my lawn mower spitting out grass. While mowing wet grass won’t ruin your garden itself, it will most definitely ruin your mood and the peace you feel while mowing.

Wet grass will clog the underside of your mower and hinder the ability of the blades to cut effectively. Due to this, the mower will spit bits of grass back out towards you.

So even though you can mow wet grass, it will only multiply your work as you’ll later have to collect all the bits and clumps of grass to ensure that your garden looks pristine and clean. Mowing dry grass is the way to go!

The Grass Might Be Too Tall

This is another bad idea. Just like with wet grass, cutting grass that hasn’t been mowed in too long and is tall will trouble you more than it will help.

Grass will clog up at the bottom of the mower and when enough grass is collected, it’ll start shooting out of the mower from all angles. This can also form clumps all over your garden and increase the work you have to put in.

You Might Be Using The Wrong Type Of Blade

Using the wrong blade can also end with this disaster of grass spitting out your mower.

Lift blades are designed to create a suction in your mower. So the grass is lifted upwards towards the blade, giving you a nice and even cut. These lift blades are available in various designs that create a different amount of suction, hence giving you a cut that you prefer.

If your blade is designed to create a higher lift, but your mower doesn’t have a strong enough engine to spin the blades with the speed required to create that lift, then a situation can be caused where the grass will be spat out of your lawn mower.

Why Is My Lawn Mower Spitting Out Grass 2
A man mows grass with an old electric lawn mower – via Flickr

The Chute May Be Clogged

If the grass that you are mowing is either long, wet, or both, chances are that the chute will get clogged up and this will cause the discharge of grass that we have referred to as spitting.

The same can happens without the grass being wet or long. If you haven’t cleaned your chute for a while, grass can build up inside it until there is no space left and the grass comes spitting out.

Your Grass Catcher Is Poorly Fitting

If the grass catcher in your lawn mower doesn’t fit properly, this can also result in bits of grass being spit out of it. This is because the clippings won’t go into the catcher in the manner they are supposed to.

Some of the pieces will go inside the catcher while others will be left behind the mower in a trail. Others will come jumping out of the mower in a manner that it’ll look like the mower is spitting grass.

The Tires Of Your Lawn Mower Might Be Underinflated

If you own a riding mower then you might have faced this problem before or at least heard about it. An underinflated tire or even a puncture in the tire can be a huge problem especially when your mower starts spitting out the grass at every angle.

The mower will lose balance, tilting towards one side as one side would be higher than the other. As a result, clippings will start flying out of the higher side.

Your Grass Catcher Might Be Covered/Thatched

We have already talked about what would happen if your grass catcher was poorly fit but we’ll also be discussing what would happen if the grass catcher is covered or thatched.

If the catcher is thatched, there will interference with the flow of air. This interference will prevent the grass clipping to be caught in the bag and as a result, grass will fly outside the mower in all directions.

Your Mower Deck Might Be Dirty

Making sure that your mower deck is clean is just as important as the rest of the point. Many people will go by years without cleaning the deck of their mower. Not only is this highly unhygienic and dirty, but it can also result in your mower spitting out grass.

If you want your mower to work properly, flip it and clean the underside. This will ensure that the clippings reach the chute and so that no grass flies out of the mower.


You need to make sure of a few important factors before mowing your lawn. Make sure that the grass isn’t too wet or long and that you are using the right blade. Check to see that the chute isn’t clogged and that your grass catcher is properly fitted and not thatched.

You need to be careful to not let your mower tires get punctured and should clean the deck regularly. This is the formula for a nice cut and pristine lawn, and for never wondering why is my lawn mower spitting out grass again. Happy mowing!