When it comes to lawn care, having the right tools and setup makes all the difference, and the most important tool in your arsenal is invariably your mower. There are dozens of major brands out there, and types, but only two mowing or discharge modes when it’s time to actually do some cutting: mulching and side discharge.
These are not actually two mower types, think of them more like mower “modes”. Many mowers can even switch to side discharge, so they can work in both modes!
You’ll find diehard proponents of each, and if you are wanting to step up your lawn care game aside from the usual mow-and-trim you give your yard, it can be difficult to figure out which one to choose…
I’m aiming to help with that decision-making process by bringing you a full comparison of mulching and side-discharge mowers… so after you read through this guide, your buying decision should be a whole lot simpler. Grab your gloves and let’s get to it!
| Factor | Mulching | Side discharge |
|---|---|---|
| Nutrient return | ✅ Excellent | Good |
| Fertilizer savings | ✅ Can reduce the amount of Nitrogen fertilizer needed by up to ⅓ | Also reduces fertilizer needs but not as much |
| Clipping size | ✅ Very fine | Larger |
| Clipping visibility | ✅ Usually minimal | More noticeable |
| Cleanup | ✅ No collection | May need cleanup |
| Tall grass | Less suitable | ✅ Better suited |
| Wet grass | More likely to clog | ✅ Generally better |
| Mowing frequency | Requires keeping up with growth | ✅ You can do it less often |
| Lawn appearance | Very neat when used correctly | Can leave visible clippings |
| Best choice | Best for regular lawn maintenance | Best for tall grass or grass that’s not mowed often |
What is a Mulching Mower?
A mulching mower is exactly what you’d think: a lawnmower that turns grass clippings into fine grass mulch. It mulches the clippings!
With traditional mowers, grass is cut and discharged to the side, on the lawn while mulching mowers, on the other hand, chop grass clippings into tiny particles. Both types redistribute the grass back into the lawn, to help to enrich it, but obviously, mulching mowers do a better job.
Mulching mowers work by using a unique cutting blade and accompanying deck that contains and chops up grass clippings into finer pieces before allowing them to settle back to the yard.
Done right, this process leads to a more natural-looking lawn without clumps of dead grass or debris left behind.
There are various types of mulching mowers, including electric and gas-powered models, and they come in push and ride-on varieties.
What is a Side Discharge Mower?
Side discharge mowers are the typical power mower you’ve probably encountered. As they cut, they eject the longer clippings in a big spray out to the right or left of the machine.
These mowers work by slicing the grass blades cleanly (more or less) and pushing the clippings out of the side chute.
The result is quick and efficient mowing, leaving a plush looking lawn but only if you clean up all the clumps.
Side discharge mowers’ biggest weakness is that they can easily spray clippings all over sidewalks, driveways and landscaping if handled poorly. Sometimes they can even eject rocks and other debris, which can and will injure you if you’re not protected given their high velocities!
Like mulching mowers, side discharge mowers come in all different types, sizes and models, from push mowers to riding mowers. They can also be gas-powered or electric, depending on your preferences and lawn size.
The Benefits of Each
There are a few major advantages inherent to each mower type…
Let’s start with mulching mowers. Mulching mowers are a great choice for the environmentally conscious because they provide a natural way of fertilizing the lawn without the use of harsh chemicals.
Those tiny clippings break down fast and nourish the soil.
There are also potential time savings when it is cleanup time: By redistributing grass clippings into the soil instead of raking and disposing of them, mulching mowers save you time and energy.
Looking at side-discharge mowers, we also see some distinct benefits.
Compared to mulching mowers, they are less likely to bog down or pack up with grass clippings, and can handle taller grass. This is because, unlike mulching mowers, the grass doesn’t have to be cut into tiny pieces – it’s just thrown out of the machine! This can also make mowing a larger are a much simpler and straightforward.
Side discharge mowers also create a more traditional, clean-cut appearance, but you might have to deal with visible clumps of grass or other debris left behind.
Ultimately, both are suitable for most lawns, and the decision to choose between mulching mowers or side discharge mowers depends on individual preferences and lawn care needs.
We’ll further unpack various factors in the next section…
When Should You Choose to Mulch?
You should choose a mulching mower if you have a smaller lawn, rarely need to mow when it’s wet, don’t let your grass get tall, or either want to reduce cleanup or actively improve the nutrients in the soil.
Mulching mowers help to return vital nutrients to the soil as the plant matter decomposes over time, such as nitrogen and phosphorus (sometimes in sizable amounts). This also saves money on additional fertilizer applications.
Problems with Mulching Mowers
Mulching mowers may incur more maintenance since they have a tendency to clog up compared to side-discharge models due to the wet grass clippings that are being recirculated, some of which will inevitably stick to the blades. But if you make it a point NOT to mow wet grass, much of the problem will go away.
As mentioned, they are slower which can negate any efficiency gains when cutting larger lawns, and they also struggle to cleanly cut wet or tall grass, so they are not ideal for anyone who is routinely dealing with less-than-ideal conditions when cutting.
When Should You Choose Side Discharge?
Side discharge mowers are ideal for anyone wanting a traditional looking lawn surface, for anyone who wants to mow quickly, or for anyone who regularly cuts longer or wet grass.
Because side discharge mowers actually create some upward suction as they cut, they tend to slice off grass clippings more neatly and leave behind a lawn that looks pretty plush.
And they don’t clog up as often or as quickly since they clippings aren’t going around and around being cut up into fine bits. They get sliced, and are kicked out of the deck.
Also, side discharge mowers are far better at cutting wet and/or long grass. Where a mulching mower would bog down, they can power through.
What are the Issues Associated with Side Discharge Mowers?
The main issue people have with side discharge mowers is that they can be messy.
The grass clippings blow around and if they are wet or stuck together you see those big mounds of grass all over, and there is always the chance that a literal wrong turn might lead to clipping all over your drive, sidewalk or flowerbeds.
That might need cleanup. This makes them less desirable for people who want a super tidy-looking lawn.
Also, even though they still deposit grass back into the yard, because the clippings are much larger compared to when they exit a mulching mower, they don’t break down as quickly. This isn’t necessarily a problem, it just means the nutrients won’t be evenly distributed…
Are Blades for Each Style Interchangeable?
Yes, to a degree, but your results can vary if you use a mulching mower blade in a side discharge mower and vice versa.
The biggest issue with blade swaps is that mulching blades tend to recirculate the clippings to chop them more finely, the opposite of what a side discharge mower does.
But there are “combination” or “3-in-1” blades that have good performance when used in any kind of mower, and they can add the performance aspects of mulching blades when used in a side discharge mower.
Can You Convert a Side Discharge Mower to a Mulching Mower?
Yes. Conversion kits are available for many side discharge mower decks. This typically consists of a blade and a cover to close the discharge port, but other things too such as discharge deflectors, baffles, etc. And, in some cases, depending on your brand and type, an entirely new deck might be required to convert.
Can You Convert a Mulching Mower to Side Discharge?
Sometimes, yes. Some models allow for an easy conversion (such as Toro machines), while others don’t.
The decks on some mulching mowers have no port to allow clippings to exit, so at the very least an entirely new deck assembly will be needed.
But others do have a discharge opening that are normally closed with a mulch plug or cover. remove the cover and set up a mulch deflector (preferably made by the same manufacturer), and you’ve got yourself a side-discharge mower!
Is There a Situation When It’s Better To Bag Grass Clippings?
Yes. Generally, you should bag clippings when you want your lawn to look as manicured as possible, particularly if you choose to take care of fertilization through other means.
What Can You Do with Bagged Clippings?
Bagged grass clippings have several uses. You can add them to your compost pile, which can provide useful nutrients to your garden.
Alternatively, you can use them as mulch around trees and shrubs – but either dried or in thin layers. So you don’t want too thick of a layer and you also don’t want the clippings directly at the base of the tree. Keep them at least 6 inches away from the trunk.
A nother thing: if the clippings have been treated with pesticides of any kind, do not use them in your veggie garden.
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Tom has lived and worked on farms and homesteads from the Carolinas to Kentucky and beyond. He is passionate about helping people prepare for tough times by embracing lifestyles of self-sufficiency.