Lawn mower mulching function. Do All Lawn Mowers Mulch? (Essential Reading)

Do All Lawn Mowers Mulch? (Essential Reading)

To mulch or not to mulch, that is the question – but do all lawn mowers have a mulching function or not?

Not all lawn mowers can mulch. Mulching mowers have curved blades and a domed cutting deck to cut, suspend and recut grass into tiny pieces that are deposited on the lawn, whereas conventional mowers have flat blades that cut just once. You can use a special kit to convert your mower to mulch.

Let’s look into the subject of mulching lawnmowers in greater detail, so you can work out if you need a mulching mower for your lawn – or not…

What’s The Difference Between a Mulching Mower and a Regular Mower?

The difference between a regular lawn mower and a mulching mower is two-fold: the shape of the body of the mower and the blade.

Regular lawn mowers use a fairly flat blade to cut grass. Once it’s cut, the blade throws the grass pieces out of the mower and onto the lawn or into a bag.

Regular lawn mowers are the choice of lawn professionals because they can use fast-moving mowers and get the job done as quickly as possible.

A mulching lawn mower cuts the grass, too, but instead of the clippings being thrown out immediately, the pieces of grass are re-circulated around a curved blade, inside the body of the mower, several times.

A mulching lawn mower has a wide, high-domed deck design that helps to suck up the grass cuttings. Some mulching mowers even have baffles built into the deck.

Not only does a mulching lawn mower have a different shape, it also has a different blade. A mulching blade is curvy, and it has a larger cutting surface. The blade’s shape helps to move the cuttings up into the domed deck, then when the grass falls back down, the additional cutting surfaces chop them up.

The grass gets suspended, chopped, suspended, chopped, until finally the pieces are so small, they fall out onto the lawn. When the pieces finally fall, they are very small – an inch or less.

This small size is perfect for mulch. Grass is mostly water. During the summer, the small pieces of grass will decompose back into the lawn in a few days.

Do I Need a Mulching Lawn Mower? (Are They Any Good?)

These days, we are all trying to do small things every day to help our planet. Mulching your grass clippings is on that list. Mulching grass clippings is a thing – it’s called grasscycling.

Grasscycling is good for your lawn and it’s good for reducing landfill volume. In many states in the US, yard wastes like grass clippings and leaves are banned from landfills.

Mulching lawnmowers work great. Sure, you might have to walk slower behind a mulching mower. But if you have a good spread of healthy lawn, a mulching lawn mower can help you cut down on the time you spend taking care of it.

With a mulching mower, there’s no raking. No stopping ten times to bag clippings. No giant piles of grass that you have to dispose of. No walking back and forth fertilizing twice a year, or more. Experts say that by not bagging, you can save up to 30% of your lawn care time.

You’ll have more time enjoying your family, grill-mastering and enjoying those Tiki drinks with the little umbrellas.

Can I Turn My Mower Into a Mulching Mower? (Can I Change The Blades?)

Several models of ordinary mowers can be turned into mulching ones with just a blade change or a conversion kit. They won’t have the domed deck design of a mulching mower, but they will mulch just fine.

First, do some research on whether your mower can operate safely without a bag. Not all can. Check out your owner’s manual or call your equipment dealer.

Many manufacturers offer a conversion kit that allows you to switch your standard (aka high lift or 2-in-1) blade for a mulching (aka 3-in-1) blade. Be sure to do some research for your particular mower manufacturer, because not all blades are universal.

It always helps to keep mower blades sharp, but it is essential with mulching blades. Experts say the rule of thumb is to sharpen blades at least yearly or every 25 hours of use.

Is it Better To Bag or Mulch Your Grass?

Environmentalists and lawn experts all say: mulch your grass if you can. Yes, there will be times when you can’t, but try to make mulching – grasscycling – your new standard practice.

The number one reason to grasscycle is that it returns nutrients back into your lawn. It helps reduce the need for chemical fertilizers.

Grasscycling can also help cut down water usage – because the cuttings are 80% water. It can help cut back on the weeds in your lawn.

No bagging helps reduce plastic volumes in landfills and all the associated microplastic issues. Here’s a great reference on the benefits of lawn mulching.

However, there are times when mulching may not work.

If you live in a wet climate, you may need to bag your clippings if you don’t get a dry spell and you just have to mow. If your lawn is too wet, the cuttings may bunch up and end up in piles on your lawn, instead of being spread out. Bunched, long clippings left on your lawn can smother it.

It’s better to bag your clippings when your lawn is suffering from a disease like leaf spot, rust or dollar spot. Get those diseased clippings out of there by bagging. Then, tackle the diseased areas.

Expert opinion is divided about mulching fall leaves. Some say that the volume of fall leaves is just too much for mulching lawn mowers to do a good job. The result is bunches of ripped up leaves on your lawn in piles, which take a lot of time to decompose and might suffocate your lawn.

Other experts say that mulching fall leaves makes for a great nutrient add to your lawn. The answer may depend on the type and volume of leaves – get the opinion of your local agriculture extension agent.

If you do bag your grass clippings, please consider adding them to flower beds and compost bins – don’t leave them stacked up in a pile of bags for the trash truck.

The good news is, for many new mowers, you can have it all. Mulching and bagging.

What Are The Benefits of Mulching?

Grasscycling helps build a healthy lawn. Mulch adds organic matter to poor soils. If your soil is sandy or clayey, mulch can improve the texture.

Grass clippings contain phosphorus, nitrogen and potassium – the same chemicals in fertilizers. Experts say that clippings can reduce or replace the need to fertilize. But if you have fertilized, be sure to mulch and not bag up the clippings (with the expensive fertilizer).

What Are The Disadvantages of Mulching?

Some experts say that if you have a struggling lawn – lots of bare patches – then mulching may actually hurt instead of help. Mulch can hide the problem areas. Experts recommend bagging the cuttings and concentrating on improving the lawn health.

Here’s an article on some disadvantages to mulching.

If your lawn has patches that are diseased, then you should bag your clippings, or you could spread the disease with the mulching process.

If you tend to leave your mowing to the very last minute and the grass is kinda long, then bagging might be better than mulching. Overgrown grass is difficult for a mulching mower to process.

The blade will slow down and rip – not cut – the long grass. Big wads of long grass can smother your lawn.

Mulching lawnmowers use a lot of horsepower recirculating the clippings. When the lawn is wet, a mulching lawn mower may not do a good job cutting and may be slow. In wet climates or wet seasons, you may need to bag your clippings.

Some experts recommend bagging if you are just starting your lawn from seed. New seedlings may not be strong enough to withstand mulch – even tiny mulch – on top of them.

Final Words

It certainly seems the case that if you want to promote good lawn health – and help save the planet – then a mulching lawnmower could be the right way to go.

‘Grasscycling’ may be a new word for an old way of doing things (I’ve been cutting the grass with a mulching mower since I was a teenager), but it now seems that climate science backs up this way of mowing.

So if you’re in the market for a new lawnmower, perhaps a mulching model is a good choice – and if you have a non-mulching mower, then maybe a blade conversion kit to make it a mulcher will be a good investment both for your lawn and the environment.

Homeowner and property investor Larry Jones founded Take a Yard in 2020 to bring you the very best outdoor living content, based on his years of experience managing outside spaces. Read more

About UsHi, I’m homeowner and property investor Larry Jones. I founded Take a Yard to bring you the very best outdoor living content. Read

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Mulching and Mower Decks

What is mulching? Why should I consider doing it? How will it make my lawn look better? Learn all about mulching now.

A John Deere exclusive. The MulchControl™ Kit with One-Touch Technology.

Grass mulch can help keep your lawn healthy and looking its best. It’s easy to do with our many lawn mower and mower deck offerings. Check out the tractor mower compatibility.

This is grass mulch.

The easy way to feed your lawn. To make grass mulch, grass is cut into easily absorbed grass clippings to help keep your lawn healthy and lush.

Mulch with the push of a button.

The John Deere MulchControl™ Kit with One-Touch Technology is the easy way to mulch. With the push of a button you can mulch when you want to.

Mulch mode.

Push the button and mulch. The chute closes and you have a dedicated mulching system. Perfect for regular, weekly, or bi-weekly mowing.

Side-discharge mow or bag mode.

Push the button again, or pull the lever, with your MulchControl™ System, the chute opens and you can side-discharge mow or bag. The choice is yours.

Eight things you need to know about mulch mowing.

Fertilizing your lawn just got easier. Just let your grass clippings do the job for you. Grass clipping mulch is the natural way to feed your lawn essential nutrients. Here are eight things you need to know:

Mulch mowing allows clippings to be cut finely enough so that they can’t be seen when redistributed into the lawn.

Make sure your blades are sharp. Sharp blades help ensure a precise, quality cut.

Mulching returns nitrogen-rich nutrients to your lawn. This feeds your lawn and can reduce the amount of fertilizer you need.

Follow the “one-third” rule when mulch mowing, taking no more off than the top third of the grass blade. Fast-growing conditions will warrant more frequent mowing.

Mulching works better when the grass is dry.

The MulchControl™ System from John Deere is the easy way to mulch while you mow.

If tall or wet grass conditions result in unsightly clumps, your MulchControl™ System should be used in side-discharge mode.

If conditions warrant using your MulchControl™ System in side-discharge mode, clippings are likely to be visible for a few days as they decay.

This exclusive technology is available with One-Touch Technology on the John Deere X350 Select Series Riding Lawn Tractor with a 42-in or 48-in Accel Deep™ Mower Deck and other Select Series mowers.

MulchControl™ Kits, with the pull-of-a-lever technology, are available on S240 Riding Mowers with Accel Deep™ Mower Decks, Select Series Mowers, Signature Series Mowers, and all Residential ZTrak™ Mowers.

All MulchControl™ Kits from John Deere include mulching blades for best grass mulching results.

The science behind mulching.

Who loves lugging a heavy bag of lawn clippings to the compost pile or yard waste bin, or endlessly raking leaves in the fall? Pretty much nobody, that’s who. Fortunately, for the sake of aching backs and nutrient-hungry lawns, it’s best to forgo the bag and opt to mulch lawn clippings and leaves instead.

Each little bit of plant material is full of nutrients, and being organic matter, when left in place, can improve the overall health of the soil which in turn, better supports the turf and potentially decreases inputs.

“In the lawncare industry, we’re realizing that rather than feed the lawn synthetically with fertilizers, we can choose to do it more organically by mulching grass clippings and leaving them on the lawn to sift in,” says Richard Hentschel, University of Illinois horticultural extension educator. “Leaving clippings on the lawn provides the equivalent of 1 pound of nitrogen per 1,000 square feet of lawn. That’s nitrogen you didn’t have to buy and apply.” Removing the clippings means also removing those nutrients from the system.

Besides nutrients, clippings return carbon to the soil, which helps build soil organic matter by feeding the microflora that decomposes that organic matter. Soil organic matter (SOM) is measured as a percentage of organic matter in the soil and is the primary indicator of soil health, and therefore the health of the lawn growing in the soil. The higher the percentage of SOM, the more nutrients and water the soil can retain.

“Every 1 percent of SOM holds 1/3 gallon of water per cubic foot of soil,” Hentschel explains. “So, a soil with a fairly good measurement of 3 percent SOM can hold as much as 1 gallon of water per cubic foot.” The ability to hold more water means more of the water applied to the soil through irrigation or falling on the lawn as rain will stay put and turf will be more resistant to swings in temperature and drought conditions.

“SOM also is Mother Nature’s slow release fertilizer. It’s not just the usual nitrogen, phosphorus, and potassium either, it’s all 16 of the nutrients essential for plant growth,” Hentschel says. Constantly removing lawn clippings and other organic matter results in decreasing levels of SOM, and lawns will become increasingly dependent on the application of synthetic fertilizers.

While lawns benefit from clippings, they don’t want to be smothered by them. Using best mowing practices can leave grass room to breathe and looking as clean as it would with bagging. The key is to mow with sharp blades and frequently enough that no more than 1/3 of the plant tissue is removed per cutting. This will result in less plant material for the lawn to reincorporate per pass.

“If you mow often with a sharp mower blade, even a conventional mower — as opposed to a mower designed specifically for mulching — will cut the grass up fine enough for it to sift back into the standing grass and break up quickly releasing nutrients to the soil and growing grass as it decomposes,” Hentschel says.

It may be a relatively simple task to stay ahead of grass to get a nice fine mulch that disappears quickly into the lawn, but what about leaves in the fall? Hentschel says to go ahead and mulch them, too. Leaves should be mowed frequently as they fall. To ensure finely parsed leaves that will move into the thatch layer more quickly, it may be necessary to make two or more passes with the lawnmower per mowing. When more leaves fall, simply keep making passes to chop up the material and help speed the composting process.

Hentschel says the leaf residue will work its way into the soil taking valuable nutrients with them and creating a barrier that can help control weeds. With multiple years of mulching leaves, which returns more nutrients to the soil through the extra organic matter, lawns may not need as much fertilizer in the spring. And because the leaf residue covers up bare spots where weeds can gain a foothold, it’s possible over time to see fewer dandelions and crabgrass issues after multiple years of mulching.

No raking, no lugging, less fertilizer, more efficient water use, and fewer weeds—for once, the easy choice is also the best choice. Go ahead and leave the mower bag in the shed if you’re so inclined, and leave the organic matter right where it belongs, on the lawn.

Mulching Grass the Right Way for a Healthier Lawn

Here in central Florida, nearly everybody mulches grass clippings. With St. Augustine, Zoysia, and Bahiagrass dominating our landscapes, it simply grows so fast that bagging and side discharging are usually impractical. But for much of the country, mulching grass is an option rather than a necessity. To get the greatest benefits for your lawn, there’s a right way to do it.

How to Set Up Your Lawn Mower for Mulching

Most walk-behind lawn mowers (push and self-propelled) come with a mulching option standard. To use it, start by taking the bagger and side discharge chute off if either one is installed.

At the back of the mower where the bagger was, lift up the rear guard (usually a plastic, spring-loaded door) and insert the mulching plug that came with your mower into the chute where grass normally travels into the bag.

Note: If your mower didn’t come with a mulching plug, many brands make mulching kits you can buy separately.

The side discharge hole (not all mowers have one) should also have a spring-loaded door that closes it up. You shouldn’t need to do anything else with it once the side discharge chute is off.

That’s it—you’re ready to mulch!

Preparing Your Lawn for Mulching Grass

Cut the Right Amount

Lawn mowers mulch grass by lifting the grass clippings into the deck and cutting them into fine pieces before they drop back into the ground. Because they need to be cut many more times than they do for bagging and side discharge, airflow is critical to the process. Airflow is created by the spinning blade, so keeping the RPMs high is important.

In general, try to mulch when you’re taking off no more than 2 inches of grass for the best results. That lets the blade speed stay up on just about any gas or battery-powered mower and get those fine pieces that send nutrients back into your lawn.

During high growth seasons (~8 months out of the year in Florida), you might need to mow every 5 days instead of once a week.

But What if the Lawn is Already Too High?

There’s ideal and then there’s practical when it comes to mulching grass. Ideally, you can cut your grass in stages—cut at the tallest height for your mower first, then drop it down another inch or two and do it again.

That’s a doable first step if you’re going to keep the lawn under control from there.

If your reality is that you’re just going to have to cut more than 2 inches at a time, you can still mulch. Be prepared to slow down or cut half-swaths in thicker sections. Remember, the goal is to keep your blade speed high, so whatever it takes to do that is key.

Cut When It’s Dry

You’ll typically get much better mulching results if you can cut when your grass is dry. That leaves the clippings lighter so they stay up in the deck longer and don’t stick to the sides.

Sometimes you don’t have a choice. During the summer, our grass takes forever to dry thanks to high humidity. And right about the time it does, sea breeze thunderstorms are about to unleash impressively high amounts of rain.

Mulching grass when it’s wet means the blade can’t cut the clippings as small before they drop out. And the wetter the grass, the more challenging it becomes, especially for battery-powered lawn mowers. If you have a choice between mowing wet grass and damp grass, go with damp.

Additional Tips for Mulching Grass

Sharpen Your Blade

Lawn mowers are powerful tools and they can still chop grass down with a dull blade. That doesn’t mean it’s doing a good job, though.

Keeping your blade sharp ensures that it slices the clippings better and keeps its RPMs as high as possible.

Change the Blade

Check to see what blade came on your mower. Often, you can replace the stock blade with a high-lift or mulching-specific blade to get even better results.

Mind Your Watering Schedule

During dry seasons when you water the lawn, try to cut the day before you water or the day of but before the sprinklers come on. You’ll be cutting when the grass is dry and you’ll immediately water in those nutrients the mulching process puts back in your lawn.

Like the mower we used in the photos? It’s a 60V self-propelled mower from Greenworks that we highly recommend. Check out our review or pick one up for yourself at Home Depot!

Should You Catch or Mulch When Mowing?

Maybe you’ve recently moved to a house with a garden, or perhaps you’ve been mowing for a while and are just wondering whether you should catch or mulch when mowing.

There are pros and cons to each method. Today we walk you through the reasons why you may choose to mulch and why you may choose to catch, with insight into the decision from local expert John Wildes.

Mulching

Mulching involves cutting the lawn without an implement on the back of the mower to collect the grass.

Pros of mulching:

• John says that mulching adds to the organic layer in the soil which is good for the health of the lawn.
• This method also means there is no waste that needs to be taken away once the job is completed.

Cons of mulching:

• Mulching leaves a layer of grass on top of your freshly-cut lawn, which can make it look less tidy than if it had been caught
• John also says that mulching can pose a problem when they grass is long or wet.

“When you’re mulching you’ll find because it’s trying to cut the grass, if the grass is a little bit long or a little bit wet, the blades start to labour a bit,” he says.

“So, it’s not cutting as well, or is as effective. It’s fine if it’s nice and dry. In the springtime and there’s good moisture or it’s rained or something, it’s going to make the disc labour a little bit. So, it’s not going to spin fast enough and cut the grass, so you’re not going to get a really good cut, in my opinion.”

John goes on to mention that sometimes grass thickness can also impact mulching results.

“Sometimes it’s not about the length of the grass, it’s about the thickness and strength of the grass you’re cutting,” he says.

Catching

When you mow a lawn with a catcher on, this device collects the cut grass, allowing you to remove it from the area.

Pros of catching:

• “Catching picks up all the waste, all the grass, neat and tidy,” John says.
• Excess grass is less likely to be picked up on feet and taken into the pool or walked through the house

Cons of catching:

• You will need to dispose of the grass cuttings that are collected in the catcher, which could come at a cost
• As you will be removing the clippings, this method of mowing can take longer than mulching.

There are pros and cons to each choice, and at the end of the day, choosing whether to mulch or catch when mowing your lawn is a personal decision.

“There is no right or wrong answer to this,” John says.

For more insight into the decision, and a demonstration of the two different choices, view our first episode of The Mow Show.