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What makes a mulching mower, a mulching mower?
Is it just the style of blade? The blades with the fans on top to do extra shredding as the blade spins?
If I had a mower that had a plane blade, can I make it a mulching mower simply by putting a mulching blade on it?

I got a free mower I'm going to fix up and then sell. But WHILE I'm selling it, I plan on using it on my yard. BUT I don't bag my clippings and I don't want to. I also don't have a chute for this mower, just the bag. If I could throw a mulching blade on this thing and use it as a mulcher, that would be ideal. If not, I might not be able to give it a proper workout/test use before selling.

The use of mulching mower would require more frequent mowing as the grass needs to be kept short.

StarTech said:

The use of mulching mower would require more frequent mowing as the grass needs to be kept short.

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StarTech said:

The use of mulching mower would require more frequent mowing as the grass needs to be kept short.

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I disagree, I cut my fescue grass at 3.5 or higher & can be cut with a mulching mower once a week.

I don't like the gator style mulching blades they don't do a good job mowing. They do a really good job mulching leave though. Put a set on mine last fall and mulched up my leave and forgot to take them off this spring. Was wondering why my mowed grass didn't look good. Decided I should clean under the deck and found the mulching blades on it I had forgotten to change. Cleaned grass from under the deck and installed a set of high lift blades and mowed the yard. What a difference it made. The problem with mulchers is. To do a good job you would have to mowe 2 or three times a week and keep the deck clean. If you mow once a week and the grass is high the clippings have no place to go and lay on top of the uncut grass. It will also clog up under the deck. Have customers buy a new mower and have a mulching kit put on it. It comes back in for a service or to sharpen the blades and the under side of the deck is all clogged up. You can have mulchers. Just my two cents worth.

I'm wondering if maybe I didn't word my question clearly because you guys seem to be talking about totally different things.

In my limited experience; Most if not all mowers can be turned into mulching mowers by changing the blades to mulching (if available for your mower) AND closing off the grass exit shoot. Some mowers come with this as an optional extra.

My view - Its a marketing con, waste of $$. Mulching requires more hp or slower operation, so more fuel consumed. I have never collected my lawn clippings - thats what worms, insects, fungi is for. Collecting your clippings is like a farmer harvesting a crop - farmers have to replenish their soil fertility after every harvest removes nutrients.

Skippydiesel said:

In my limited experience; Most if not all mowers can be turned into mulching mowers by changing the blades to mulching (if available for your mower) AND closing off the grass exit shoot. Some mowers come with this as an optional extra.

My view - Its a marketing con, waste of $$. Mulching requires more hp or slower operation, so more fuel consumed. I have never collected my lawn clippings - thats what worms, insects, fungi is for. Collecting your clippings is like a farmer harvesting a crop - farmers have to replenish their soil fertility after every harvest removes nutrients.

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Mulching grass versus throwing grass as far as it will go out of the exit chute, is a no brainer. Mulching is for the birds.

I find it difficult to fully understand how mulching works. How can a grass blade be cut and recut while it is spinning in the same direction as the mower blade tip is pushing it? How can a mower deck that is designed to lift the cut grass and keep it in suspension also distribute the final mulched clippings with no exit chute? Sure you may be able to pulverize the clippings but the windrowing and clumping and deck clogging all together defeat the idea of the desired mulching benefits. If you are cutting 6" grass to 4" are the mulched clippings any smaller than the side discharge clippings Do those mulched clippings actually decompose any faster? Any better? All of the clippings either way are returned to the turf and to the thatch and eventually to the soil. In a perfect world, maybe mulching is a good option but I have never been able see any real proof that mulching is significantly better than side discharging.

bkeller500 said:

I find it difficult to fully understand how mulching works. How can a grass blade be cut and recut while it is spinning in the same direction as the mower blade tip is pushing it? How can a mower deck that is designed to lift the cut grass and keep it in suspension also distribute the final mulched clippings with no exit chute? Sure you may be able to pulverize the clippings but the windrowing and clumping and deck clogging all together defeat the idea of the desired mulching benefits. If you are cutting 6" grass to 4" are the mulched clippings any smaller than the side discharge clippings Do those mulched clippings actually decompose any faster? Any better? All of the clippings either way are returned to the turf and to the thatch and eventually to the soil. In a perfect world, maybe mulching is a good option but I have never been able see any real proof that mulching is significantly better than side discharging.

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Mulching is for people that like the idea or theory of mulching. In practical real results it fails. Sure if you were cutting perfectly dry grass about 1” off the top, it works ok, but how often does this happen? Mulching doesn’t even work that well for a 21” mower in thicker and taller grass. Remember, the grass has nowhere to go. I try to educate and help my customers in issues such as this, and they actually listen many times.

Tiger Small Engine said:

Mulching is for people that like the idea or theory of mulching. In practical real results it fails. Sure if you were cutting perfectly dry grass about 1” off the top, it works ok, but how often does this happen? Mulching doesn’t even work that well for a 21” mower in thicker and taller grass. Remember, the grass has nowhere to go. I try to educate and help my customers in issues such as this, and they actually listen many times.

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I agree. And if you are only taking off an inch at a time how could any of the 1” clippings ever get recut?

I only mulched with my EGo 21" SP electric mower. Basically you need a blade with high lift on the outer portion, down blowing in the center, so that clippings circulate. Sometimes I bagged so as to have clippings to cover bare ground.

Have not been mulching with the ZTR as it blows grass 10' or more and doesn't leave any visible clippings if I cut every 5-7 days. About the time some of my grass goes to seed.

I don't know if I missed the answer to the gent's question or if it didn't get answered. "What makes it a mulcher?". To me it means blocking off the shoot, adding a plug\baffle and mulching blades. I have 2 ZT, one for mulching my front lawn and the shoot for the back 40. The mulcher does a great job if the grass is kept shorter and cut when dry. The shoot doesn't care, but it leaves a coating of cut grass on the top. For leaves in the fall. the shoot just blows them a mile whereas the mulcher grinds them up.

Definition......Grass mulching or circular grass managementIt is a specific mowing technique that finely shreds the grass into small particles. These small particles are then blown back over the lawn and evenly distributed between the grass. In a perfect situation I would agree. In real life there is a strong tendency for the re-distribution to not occur evenly, resulting in clumping, windrowing, underside deck accumulation and/or uneven cuttings. Many factors influence the final outcome. The equipment, the operator, the lawn health, moisture and terrain all are part of the equation. Any mower will mulch to a degree. Chute blockers and blades are options but not the only determining factors.

l008com said:

I'm wondering if maybe I didn't word my question clearly because you guys seem to be talking about totally different things.

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That happens frequently on this and other boards!
To help with your question, A mulching mower is comprised of two main components that makes them work correctly. 1) the blades are curved to create more lift and has a top side cut, and 2) the deck needs to accommodate a mulching "plug" or kit so that the cuttings are re-cut continuously and not discharged. I have a neighbor that claims he has a mulching mower but when I look at it the only thing he has is the mulching blades and his deck discharges which does not make it a mulching mower. I told him to check his model to see if the manufacturer had a mulching kit available to complete the mulching requirements. Discharging the grass defeats the purpose of mulching.

With that being said, I don't see mulching as a good solution for a walk behind mower. I have a 54" Z-Turn with mulching kit and blades and works great!

l008com said:

What makes a mulching mower, a mulching mower?
Is it just the style of blade? The blades with the fans on top to do extra shredding as the blade spins?
If I had a mower that had a plane blade, can I make it a mulching mower simply by putting a mulching blade on it?

I got a free mower I'm going to fix up and then sell. But WHILE I'm selling it, I plan on using it on my yard. BUT I don't bag my clippings and I don't want to. I also don't have a chute for this mower, just the bag. If I could throw a mulching blade on this thing and use it as a mulcher, that would be ideal. If not, I might not be able to give it a proper workout/test use before selling.

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take off your bad, the mower will likely have a trap door....blades are designated mulching blades because of the design. mulching puts the grass back on your lawn to self fertilize...and a mulching setup means you don't have to go in only one direction around things....Preferred. here in florida you have to cut once a week anyway...so the clipping are never that bad and they are mulched up and returned to the lawn...

dberry1052 said:

take off your bad, the mower will likely have a trap door....blades are designated mulching blades because of the design. mulching puts the grass back on your lawn to self fertilize...and a mulching setup means you don't have to go in only one direction around things....Preferred. here in florida you have to cut once a week anyway...so the clipping are never that bad and they are mulched up and returned to the lawn...

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I live in north Central Florida and have mowed with Mulching plugs and blades on 7 acres for 20 years. No clumping from discharge and I don't use a push mower.

Mulching, is a way of processing grass clippings into smaller pieces. The more you process the more energy/power is required.
Two identical mowers, one with a standard cut system, the other with mulching - The mulching mower will use more fuel, likly cut slower and all for a very questionable benefit.

Totally disagree but I think you're comparing a push mower and I use a 25HP zero turn with great results and have for years!

I don't doubt mulching requires more power. The grass blades are cut multiple times, each cut requires power.

As for the benefit? Not questionable at all. Is a bit silly to pay to fertilize, then cut and bag clippings to discard. Rather, chop them up, put them back on the ground, keep the nutrients where they are needed.

Expected to add a mulching kit to my zero turn but so far it cuts clippings fine enough not to be laying on top turning brown. Maybe I'm mowing too often?

Gentlemen:
More Power:
Retired now but whole career in agriculture. Doesn't matter what you are processing, the more you process (in this case render the grass clippings smaller) the more power is required - simple physics.
No matter the size of your machine (push or ride on), an identical one, without mulching kit, will use less power than the one that has it. This can be translated in to less fuel burnt per unit area (acres or hectares) or less time to cut.
Fertilizer:
I have never removed grass clippings from my lawns - thats what worms/fungi/insects are for (incorporating organic matter). Removing grass clippings is much the same process as harvesting/grazing a crop - by doing this you are stripping nutrients from the soil, leading to nutrient deficiency. If you want to maintain a health grass cover/lawn, you will have to replace the nutrients lost, by fertilising (chemical or organic). In my view a crazy notion.
Blades Cut Multiple Times:
There will always be a degree of material "churn" within the cutting cavity - its just not possible to eject each cut grass clipping without some recut However this is not the intention. If your mower deck has been correctly adjusted, there will be minimal recut/processing.
Think of the blade as a disc, with one side, half of the disc, being the forward/leading edge (cutting arc). For most effective, least power required, operation, the disc should be set so as to achieve a leading edge down angle ie as the leading edge leaves the cut sward, so its trailing edge (arc) should be fractionally above the cut material. No additional cut or drag, so lowering hp requirement.

Mulching does require more power but not because you are cutting the clippings multiple times
It requires more power because you are pumping more air, a lot more air to keep those clipping airbourne .
This assumes you are not trying to mulch 2' tall grass

Maaaate!

A conventional mower deck is similar to a centrifugal pump/aircraft propeller. Cut off the air supply/exit (as in a mulching mower exit plug) you use less power and move less air.

Most mowers use blades with a "pitch"/twist so as to act as fan/propeller. Propellers are just a type of (air) pump. The fan function is two fold. Air is drawn in, usually from the underside of the deck "skirt" to lift the sward, for the blade leading edge to cut. The combination of air and clippings, plus acceleration imparted by the blades on the clippings, is then used to blown the cut material out of the the exit shoot.

My limited understanding of how a mulching mower works is:

• Fitted with blades designed to enhance the break down (mulch/render) of the grass clippings, by additional impact (cutting) and then force the clippings into the sward/lawn.
• Exit shoot is usually blocked, so that the clippings will be retained within the deck cavity, thereby facilitating the additional processing of the clippings.
• The blocking of the exit shoot reduces the effectiveness of the fan function (blocks exit air) - to try & counter this, mulching blades may have courser pitch blades.
• The concept of a mulching mower, is that extra fine clippings created, will be forced into the sward for more rapid decomposition/incorporation (little evidence), unsightly (to some) grass swath may be eliminated and for those inclined to removing grass clippings, this action will not be required.

Doesn't matter what a machine is processing (grass/grain/gravel/etc) - the more its processed, for a given throughput, the more energy is required.

Reduce the throughput (slow the mower &/or raise the deck) and reduce the energy/hp needed & visa versa.

It's called physics and even Einstein worked within its laws.