The Best Mulching Blades for Mowers   

Attaching one of these clump-busting blades to your mower can help make your lawn more beautiful and healthy.

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The Best Mulching Blades Options

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You work hard to mow your lawn, yet can wind up with ugly clumps of cut grass sitting atop that manicured expanse of green. Even folks who want clippings to return to the soil as nutritional mulch won’t reap many benefits from big balls of grass. The solution to these troublesome tufts of turf is to break them up during the cutting process with a mulching blade, which can help disperse clippings properly so that they break down efficiently into the soil.

At first glance, a mulching blade might not look very different from a standard mowing blade. They’re similarly-shaped and install on the same mounting holes. But while standard blades are relatively flat, with very little angle, mulching blades are designed somewhat like an airplane propeller, with the rear of the blade angled upward (known as the lift). This pushes grass clippings into the bagger with more airflow than a standard blade. Many mulching blades also have teeth (similar to a serrated knife) cut into the lift. These teeth slice through grass clumps, dispersing individual blades of cut grass into the bagger (if attached) or onto the ground so they can make their way back into the soil.

Adding mulching blades to an existing mower is a snap for any DIYer with a socket set. And while most are designed for gas-powered mowers, you can find mulching blades to suit an electric model, too. So, to keep your lawn looking great after mowing and create rich mulch for it as well, learn what to look for in mulching blades and consider what makes these eight options superior.

  1. BEST OVERALL: Rotary Copperhead Toothed Mulching Mower Blades
  2. BEST BANG FOR THE BUCK: MaxPower 21-Inch Universal Mulching Lawn Mower Blade
  3. BEST FOR RIDING MOWERS: Oregon G3 Gator Blades
  4. BEST FOR ZERO-TURN MOWERS: 8TEN LawnRAZOR Mulching Blade Set
  5. BEST FOR PUSH MOWERS: Maxpower 21-Inch Universal Mulching Blade
The Best Mulching Blades Options

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What to Consider When Buying Mulching Blades

While professional landscapers are familiar with these hopped-up grass-shredders, mulching blades will likely be a new concept for many homeowners. Here are some things to consider before buying a mulching blade for your push or riding mower.

Length

Long story short: Having the right length mulching blade for your mower is crucial. Mowers and all of their components are designed specifically for a certain length of the blade. Installing a too-small blade will provide less than optimum results in three ways:

  1. You’ll make more passes (i.e., work harder), as the cutting area your mower can cover is now smaller.
  2. For multi-blade mower decks, you’ll be missing small strips of grass altogether, leaving the lawn looking like a mosh pit with multiple Mohawk haircuts.
  3. Your bagger will be ineffective due to the lack of airflow that a smaller blade provides.

Blades that are too large will slow your mower down considerably if they even fit under the deck. As well, you’re likely to cause more clumping due to the slower speed and the lack of space under the deck that the larger blade creates. Plus, a blade that is too long can be a hazard, potentially striking the mower’s body or another blade in a double- or triple-blade mower deck.

Most lawnmowers display their cut size on the side of the mower (22-inch, 48-inch, etc.), so check your model to find the appropriate length. If it’s not there, refer to the owner’s manual under the replacement parts section.

Weight

Mulching blades are considerably heavier than standard mower blades. They’re thicker, and the design of the more aggressive lift angle requires more material by default. Because of this, they may cause your mower to run slower. Users with older riding mowers may find that their mower wants to stall when engaging the deck. The increased inertia of the mulching blades provides more resistance than the mower was designed for.

While this is a necessary evil in the mulching process, you may avoid blade-induced bogging if you stop the mower before engaging the cutting deck. This will reduce the amount of strain on the engine and once the blades are up to speed, the machine should be able to function without complaint or sputter.

Number of Pieces

If you’re looking to upgrade the blades on your riding mower, you’ll want to purchase a kit with the correct number of blades. Most riding mowers have two or three blades, and all should be replaced with matching blades for optimum mulching performance.

Replacing only one mulching blade is a bad idea for two reasons.

  • You probably won’t see the benefit of better airflow or mulching, as the standard blades will still cause clumping.
  • Since mulching blades are much heavier than standard blades, installing differently weighted blades will disrupt the mower’s output, as one blade will run slower than the other. This can result in turbulent mowing and a less enjoyable experience for the user.

Fitment and Mounting Options

There are several different mounting hole styles on today’s mowers; most commonly, five-point star, six-point star, bow-tie, and universal fit. The spindle (where the blade attaches) under the mower deck is designed for one of the shapes listed above, and blades matching the spindle should install with ease. The easiest installation methods tend to be the five-point and six-point stars, as they only require the user to remove one bolt. Universal kits are not always the best option since they’re not designed specifically for any specific mower, but they do take the guesswork out of which blade is right for your mower.

The Durability Dilemma

Mulching blades are more durable than standard mowing blades due to their thickness and design. That’s an asset for riding mowers and commercial machines with belt-driven decks. For push-mowers with direct-drive shafts, however, this durability can be a problem. Here’s why:

For belt-driven decks, blades are attached to spindles, which are then attached to pulleys. A belt connects all the pulleys while also being attached to the drive pulley on the motor. When a thick mulching blade hits an object (like a stump or rock), it will most likely slip a bit on the belt—a built-in fail-safe. The blade may bend, but the mower itself won’t be damaged (aside from maybe shortening the lifespan of the belt by a small margin).

For direct-drive mowers, like standard push mowers, blades are attached directly to the mower’s output shaft without a belt or pulley. This allows the smaller motor to spin the blade very quickly, but it doesn’t provide any fail-safe capability. A standard blade will bend if it hits a stump or rock, most likely leaving the mower intact. A thick mulching blade won’t give as easily and can quickly result in a bent output shaft—fatal for most push mowers.

Ideally, regardless of mower style, try to give your lawn a quick check before you start mowing to remove any obstructions or make a mental note of immovable impediments. Lifting the deck height a bit will also avoid issues; however, you’ll need to cut the lawn more often.

Our Top Picks

The Best Mulching Blades Options: Set-of-3-Mulching-Blades

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BEST OVERALL: Rotary Copperhead Toothed Mulching Mower Blades

For homeowners looking to level-up their grass mulching game, this set of three mulching blades from Rotary could be just the ticket. This set is designed for any 48-inch mower from Craftsman, Poulan, and Husqvarna, thanks to its five-point star mounting hole. These blades are 16¾  inches long, 2½  inches wide, and a hefty .187 inches thick. The serrated teeth at the back of the lift will direct the cut grass easily into a bagger, keeping clippings off your lawn. But if you skip the bagger, these blades are likely to leave a few clumps that might require raking.

The Best Mulching Blades Options: Maxpower-331981B

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BEST BANG FOR THE BUCK: MaxPower 21-Inch Universal Mulching Lawn Mower Blade

MaxPower knows that not everyone has the time or patience to consult user manuals and part numbers to find the exact model number of their lawnmower. So they designed their 21-inch mulching blade to fit any push mower with a 21-inch deck. The mounting hole is designed to fit over both five-point stars and bow-tie shafts, so users can install this mulching blade easily. To make the process even smoother, all washers and fittings required for mounting on most models are included. This 2-1/4-inch wide blade has a steep lift and more importantly for mulching, seriously aggressive teeth for crushing clumps. One caveat: this blade is durable enough to take a hit without bending, which means your mower’s output shaft could get damaged if you go over a stump or rock.

The Best Mulching Blades Options: Oregon-G3

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BEST FOR RIDING MOWERS: Oregon G3 Gator Blades

If you’re ready to replace the blades on your 54-inch Craftsman, Ariens, or Husqvarna riding mower, get this set of G3 mulching blades from Oregon. The blade set is extremely heavy duty and durable, thanks to their 2-3/4-inch width and .187-inch thickness. They have an aggressive lift and a set of serrated teeth to break clumps up quickly and efficiently.

The Best Mulching Blades Options: 8TEN-LawnRazor-Mulching-Blade-Set

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BEST FOR ZERO-TURN MOWERS: 8TEN LawnRAZOR Mulching Blade Set

For homeowners and landscapers with zero-turn mowers, this blade set from 8TEN can be a terrific upgrade. Each blade is designed to fit 48-inch decks from such mower manufacturers as Gravely, Scag, Hustler, Toro, and John Deere. They’re designed with durability in mind, at 2-1/2-inches wide and with a thickness of .197 inches. The 8TEN blades can rip through the grass and mulch clippings with ease. Plus, their powder-coated finish helps keep them in great shape despite hard use. Keep in mind that these blades work best in dry grass, so they aren’t ideal for early morning landscaping jobs or post-rain cuts.

The Best Mulching Blades Options: Maxpower

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BEST FOR PUSH MOWERS: Maxpower 21-Inch Universal Mulching Blade

This universal model from MaxPower takes the guesswork out of choosing the best mulching blade for your 21-inch push mower. It’s all about easy installation and includes all the washers and fittings needed to work on most mowers. It’s a high-lift blade, meant to send clippings directly into a bagger, and at 2-1/4 inches thick wide, it’s light enough to work for most 21-inch mowers without issue. The blade lacks serrated teeth, so it works best with a bagger, not for leaves or for letting grass clippings settle in the soil.

FAQs for Your New Mulching Blades

Mulching blades are likely a new concept to folks who do their own yard work. Here are some answers to common questions homeowners often have.

Q. Is mulching better than bagging leaves?

Mulching allows leaves to break down into organic fertilizer much faster, and it’s less work for a homeowner. For homeowners who hate raking and bagging leaves in the fall, mulching is undoubtedly the better solution. If you use a bagger, you’ll be able to dump leaf litter in a garden bed for organic matter, or past the woodline where they can break down into the ecosystem.

Another option is to simply shred the leaves into leaf litter and leave them on the lawn. This looks a little messier than bagging but can enrich the soil over the course of the winter. As the small leaf particles work their way between the blades of grass, they’ll break down and leech nutrients into the soil.

Q. Can you install mulching blades on any lawn mower?

There are mulching blades available for most mowers, but not all mowers should have mulching blades installed. Underpowered models may not have the horsepower to spin a heavy mulching blade at an effective speed, providing mixed results when cutting and mulching.

Q. How often should I mulch my lawn?

You can use your mulching blade year-round. Most homeowners that install mulching blades don’t bother changing them until they become too dull to cut effectively, in which case they’ll have them sharpened.