Do Mulching Blades Face Up Or Down? (Installation Tips)

There’s a great variety of mulching kits on the market, and they keep getting better and better. However, no matter how good your mulching kit is, if it’s installed incorrectly, it’ll cause harm to both your mower and your lawn. 

Do Mulching Blades Face Up or Down?

The blade edge’s cutting teeth will face you while the teeth or flaps face the deck. If you’re unsure how to install it, follow the owner’s manual or consult the manufacturer’s website. 

Installing mulching kits, especially the blades, can be confusing at first. For example, you may not be able to figure out if the mulching blades are facing up or down. 

But don’t worry; we’re here to help with just that. Let’s know more about mulching blades, their notable features, and how to install them correctly.

What’s the Difference Between Mulching Blades and Regular Blades?

Before thinking about installing your mulching blades correctly, here’s some essential info about them and how they differ from your regular mowing blades.

Grass Discharge Features

The primary purpose of mulching blades is to produce mulch for the lawn. When grass is cut using a mulcher blade, it isn’t discharged, but rather it’s sent back to the deck to be re-cut and recycled.

Meaning if you want grass discharge and strips on your lawn, regular blades would be the better pick for you.

Depending on the mower you’re using, regular blades either discharge the grass clippings to the sides or inside the bag if your mower comes with one attached to it. 

This means that while mulching blades are efficient, their lifting capacity is lower than regular blades because of their recycling process.

Shape, Compatibility, and Time Management

The critical difference between mulching blades and regular ones is the curved edges in terms of shape. The edges on mulching blades are much more curved, and they can either have sawlike teeth or be flat. 

This shape makes mulching blades more efficient because the grass moves more easily through them when recycled under the deck.

It’s also important to note that mulching blades are more compatible with many different mower models, and they’re more durable. On the other hand, many regular blades aren’t compatible with most of the newly released mowers on the market.

They can save you tons of time because, with mulching blades, you don’t have to worry about removing a lot of discharge and cleaning up your lawn.

However, you should note that mulching blades might not do the best job on wet grounds. They also need more horsepower compared to regular blades.

It’s recommended to mow your lawn every four to five days if you use mulching blades and every 10-15 days if you use regular ones.

Now that we’ve learned more about mulching blades let’s know which way they should be facing and how to install them correctly.

Should Mulching Blades Face-up or Down?

When you purchase your set of blades, you’ll probably wonder which side of the blade should be pointing upward and which should be downward. 

You should first check the user manual; you’ll probably find all the help you need there. However, if the instructions aren’t self-explanatory on it, you’ll still be able to figure it out.

This video walks you through properly installing a new blade on a lawnmower.

Determining Which Side Faces Down

Some blade sets make the job easy and come with writing or numbering that indicates which is which, so the first thing you should look for is writing on either side that says “bottom.”

Some newly released mulching kits are even fancier and come with bright stickers that mark the bottom side. Some even come with engravings on the bottom side that say something like “bottom-side” or “towards the grass.”

However, if your set doesn’t come with writing, numbering, stickers, or engraving, you should determine your blade’s sharp and dull sides. The sharp side should look to the ground because this is the side that does the cutting. So face the sharp side down to the soil, and the dull side up to the deck.

You may wonder what happens if you install your blades upside down by accident. If this happens, the sharp edge will be pointing towards the deck, which means you’ll end up scratching your mower and have no grass cut. So make sure you figure out the sides well before the installation.

Sharpening Your Blades

Now that you’ve determined which side goes where you’ll need to sharpen your blades. If they’re brand new, you likely won’t need to do this step.

However, if that’s not the case, you should sharpen the sharp edge from the top down. But, again, only this part is required, not the whole thing.

The perfect angle to sharpen them is a 45-degree angle, and your sharpening tool should be around nine to ten inches to give you the right results. You can use either a file or grindstone— both are inexpensive and readily available. 

Keep in mind that you shouldn’t make your blades razor-sharp because that will only cause them to dull faster and be more susceptible to dents and breakage.

As for how often you’ll need to sharpen your blades, it would be ideal to sharpen them after every 25 to 30 hours of mowing. And if you’re consistent, you’ll need to change them once a year.

How to Install Mulching Kit and Blades

Before installing your mulch blades and kit, make sure to read the instruction manual that comes with the equipment very well and go through the safety measures.

The installation process will require you to work under the deck, meaning you can either lift the front of the mower. If you don’t have a lift around, you can remove the deck and start working from there. 

  1. First, you’ll need to remove the chute. To do that, you’ll need to remove the screws that hold the discharge chute bracket to the deck, then remove it slowly.
  2. Next, if you already have regular blades on your mower, you’ll proceed to remove them. Be mindful of all the blades, not just the one you’re removing, because the movement of one blade will rotate the others.
  3. Afterward, start removing the screws on the top of the deck and begin installing the left baffle. Secure it with the two nuts that come with your kit, make sure they’re well secured, and repeat the process with the rest of the baffles.
  4. Then, start installing the mulching blades, keeping in mind the points we mentioned above. Remember, sharp side to the ground and dull side to the deck. After you place them correctly, secure them with the hardware screws.
  5. Repeat the same steps to install the rest of your blades. Keep in mind that while you’re tightening the hardware, you’ll need to block the movement of the blades so they don’t injure you with their rotation. You can block them with any available sturdy tool, preferably a wooden item.
  6. The last step would be to double-check that all your hardware screws are tightened well. Any shaky screws can cause a severe problem when the mower is turned on, so be careful of that.

After that, your mower is ready and good to go!


The process may seem confusing at first, but with a bit of patience, you’ll be able to install your mulching blades correctly and efficiently. 

Most instructions manuals will tell you what to do, but it’s better to be aware of the process yourself. You never know when one of your kids will decide to throw the manual out! 

So it’s always good to have a backup.

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