How to Remove Dried Grass from Lawn Mower Deck (My Go-To Method)

I have two different lawn mowers in my shed. One is a push lawn mower, and the other is a riding lawn mower. One thing I have perfected over the years is figuring out how to remove dried grass from the lawn mower deck, including the very stubborn grass mixed with dirt.

So, if you are struggling to find an easy and thorough method of cleaning your lawn mower deck, then let me share with you the two methods I use. Let’s take a look.

Best Way to Remove Dried Grass from Lawn Mower Deck? (The Short Answer)

For smaller push lawn mowers, I find the best way to clean the deck is to tip the mower over and use a selection of cleaning tools, including scrapers, screwdrivers, and a garden hose. For larger lawn mowers, I find that removing the cutting deck gives better access and allows for a more thorough job using the same cleaning tools.

Why Dried Grass on a Mower Deck Can Be a Big Problem

The space under the cutting deck needs to be kept clear of dried grass and dirt so that the blades can do their job efficiently. This includes things like cutting, mulching, shredding, and generating enough airflow to make the bagging and discharge systems work properly.

If you have large amounts of grass stuck to the inside of your cutting deck, you might find that your lawn mower won’t cut your lawn evenly and that your deck and chute are continuously getting clogged. This is definitely an issue if you are trying to use a collection bag on your lawn mower.

How to Remove Dried Grass from Lawn Mower Deck (This Usually Works Great)

So, let me share with you my two methods for cleaning cutting decks. These methods give me really good results and don’t cause any problems with the function of my lawn mower. Let’s take a look.

Push Lawn Mowers Deck Cleaning

• Wet Down the Dried Grass – The first step is to soak the dried grass so it’s not so tough. For this, I just use a steady stream from my garden hose.
• Allow the Dried Grass to Soften Up – Once I have the grass soaked with water, I then give it five or ten minutes to really soften up. I find the longer I leave the lawn mower, the easier it is to remove the grass.
• Scrape Off the Bulk of the Grass – Next, use a two-inch scraper and start working on the dried grass. For tighter spaces, I switch over to a long-handle flathead screwdriver. I don’t try to get all the grass off in one go. I just go for the bulk to start with.
• Re-Wet the Remaining Grass – Again, spray dried grass and allow it to really soak in. Letting it sit for five or so minutes really helps.
• Continue Scraping – So, here we are going to repeat the cleaning process. This time, I like to also use kitchen non-scratch scouring pads. One of those green scouring pads you use to clean cooking pots.
• Rinse & Repeat – Next, I grab my garden hose, rinse the area, and then go back to the previous steps. My lawn mower deck looks pretty good after a couple of goes with soaking and scraping.

While you’re getting your hands dirty, it makes sense to check that the blade is also nice and clean too, as a dirty blade can also affect cutting/mower performance. I put together a guide about the process I go through to do that too, which I’ll link to below.

• How to Clean Lawn Mower Blades

Riding Lawn Mower Deck Cleaning

When it comes to how to remove dried grass from a lawn mower deck on a riding lawn mower, the only difference for me is how I get to the underside of the deck. So, for the push mower, I tip the mower, and for my riding lawn mower, I remove the cutting deck.

Usually, this process requires you to remove the deck belts and then remove a few clips holding the deck bracket in place. So, once the deck is disconnected from the lawn mower, you should be able to slide the deck out and flip it over.

Next, I use the same cleaning tools and techniques I use on my push mower to remove the dried grass.

Things to Be Careful of When Trying to Remove Dried-On Grass from a Mower Deck

When you are cleaning a mower deck, there are a few things you will want to be careful of. This could save you from some pretty extensive repairs. Let’s take a look at what these are.

Tilting Over the Lawn Mower

If you are about to head out to clean the deck on your gas-powered push lawn mower, then you’ll want to make sure that you tilt over your lawn mower the correct way. If you happen to do this incorrectly, then you’ll end up filling the carburetor and the air filter will oil from the bottom of the engine.

So, when you tip over your lawn mower, make sure you tip it the right way with the air filter pointing upward. This will save you from having to spend more time fixing your lawn mower’s carburetor and air filter.

Removing Paint From Inside the Cutting Deck

If you go too hard with the scrapers and other tools, then you might end up removing some paint from the inside of the lawn mower deck. Unfortunately, this will end up rusting and causing you a whole bunch of new problems. Rust on the underside of the cutting deck can lead to problems like holes and a weakened deck.

So, if you do happen to chip off or blast off some paint, be sure to repair it so that it doesn’t lead to rust. If you skip this process, then you’ll probably be carrying out rust repair to your cutting deck at some point in the future.

Getting Water into Pulleys

When you are working on larger decks, like a cutting deck on a lawn tractor, then you’ll have a number of pulleys that drive the blades. These pulleys are sealed to keep the grease inside, but high-pressure pressure washers have enough power to get past the seals. Just be careful how close you get to the deck pulleys.

Getting Water into the Fuel Tank

The next item I see giving people trouble is getting water into the gas tank when using garden hoses and pressure washers. Anytime I use one of these tools to clean my mower deck, I put a plastic bag between the gas tank and the filler cap.

To do this, all you need to do is remove the gas cap, place a plastic bag over the gas tank, then replace the filler cap. This stops any water from getting through the filler cap vent and into the tank.

Getting Water into the Engine

The last thing to watch out for when cleaning a mower deck is getting water into the engine. There are two places where this can happen. First, water can get into the air filter, which runs into the carburetor and then into the cylinder head. Second, water can seep through the seal in the drive shaft.

Again, like a pulley on a cutting deck, you need to be careful not to blast water with a pressure washer against the drive shaft seal. If you do, then you could get water into the sump of the engine, which will lead to problems with lubrication and corrosion.

Why I Don’t Use Pressure Washers to Remove Dried Grass

I have a pressure washer in my garage, and I use it a lot but not for cleaning my lawn mower deck. This is because they cause more problems than they are worth and can make a real mess by blasting grass clipping all over the place. Usually, I find that you spend more time cleaning up your work area after using a pressure washer than you do actually cleaning the intended object.