What the Heck is a "Dedicated Mulching Mower"?

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Q. I've heard you say many times on your *Awesome Radio Program* that {quote} "you need to get a dedicated mulching mower". But I've never heard you say exactly which ones you consider "dedicated". I've looked at the Toro line of 'recyclers' and a Honda model that has twin blades. Are there others I'm missing? Am I way off the mark? "Help me Obi-Wan Kenobi; you are my only hope".

---Paul in Collegeville, PA

A. You stole—and reversed—my punch line, Paul! Because I would have said, "those ARE the droids you're looking for". And many other mower-droids can also battle The Dark Side of lawn care for you.

Now, I probably shouldn't continue to use the term 'dedicated', because what I'm trying to specify is a mower designed to {quote} 'mulch' tiny little bits of your cut grass back into the turf (as opposed to older-style mowers that ONLY give you the option of bagging everything up or shooting full-sized clippings back onto the lawn). It sounds like the mowers you've been looking at—and most of the mowers available to today's homeowners—are designed to mulch.

Technically, a really 'dedicated' mulching mower would not give you any options. My mulcher (a Black & Decker electric) happens to be such a mower; the desk is sealed tight and there doesn't seem to be any option for attaching a bag. And I don't want a bag. I don't otherwise feed my lawn (it's out in the back where nobody sees it and is pretty much only there for erosion control) and so I want it to get all the potential benefit of the returned clippings.

But this is great timing, as lawn care season is 'opening' as we speak. So let's discuss 'feeding your lawn as you mow'; and address the two worst phrases in all of lawn care: "Mulching mowers" and "leaving your clippings lay on the lawn."

I don't know who actually coined the term 'mulching mower', but I would like to slap them silly. As Tom Hanks could have said in the great baseball film "A League of Their Own": "Mulching? There's no mulching! There's no mulching in lawn care!" The word 'mulch' refers to anything you place on top of the soil to prevent weeds and retain moisture. Two inches of compost makes an excellent mulch in flower beds and other bare-ground applications. Shredded fall leaves are my mulch of choice in the vegetable garden, as earthworms rapidly colonize the cool, damp soil underneath the leaves, creating lots of rich worm castings that feed the adjacent plants naturally.

Wood, bark and root mulches can be useful in certain situations, but they can also be highly problematic; especially when used near light-colored homes or cars or when they're allowed to touch the trunks of trees or stems of plants. They're over-promoted and over-used because landfills no longer accept wood waste, and gardeners always seem to be the first targets of people with waste disposal problems. Read our previous articles on wood mulches (in the archives under "M") before you imitate people who are staining their homes and killing their trees.

So, where's the actual 'mulch' in a mulching mower? There isn't any! You don't want to spread mulch over your lawn; that would be bad. What mulching mowers actually do in their mulching mode is trap the cut grass blades inside a sealed deck and cut them repeatedly with a super-sharp blade, insuring that what eventually drops back down onto your lawn is in the form of a fine powder. A fine powder that just happens to average 10% in nitrogen content.

Lawn care experts estimate that returning these perfect nitrogen-level clippings to your lawn in pulverized form provides half the food the average lawn needs in a given year. It's also the only safe way to re-use clippings from a lawn that has been treated with chemical herbicides or pesticides.

Ah, but the big thick clippings that older mowers shoot out the side are a darn good imitation of mulch; they can smother a lawn—and they take forever to break down. So if you can actually SEE 'clippings left on your lawn', don't leave those clippings on your lawn! Many older mowers can be retrofitted to do a fairly good impression of a real mulcher by sealing up the exit hole and replacing the old blade with a sharper one.

But if your mower is really old and gas powered, you're not doing your lawn or the environment any favors by keeping it in use. Those old two-stroke engines are real stinkers, while modern mowers have great emission controls. Your state or municipality may even give you a trade-in/rebate kind of incentive to get your old clunker out of circulation. (A bailout for the Bay; stimulus for the seas!)

Your choices in a new model will be a truly dedicated mulcher, where you can't collect any clippings; or a multi-purpose mower where you can mulch or bag. If you don't use lawn chemicals and want to make great compost, a multi-use machine can be a great choice for fall mowing. Go over a leaf-covered lawn with the bag in place, empty that bag—containing the perfect combination of well-shredded leaves and nitrogen rich lawn clippings—into a big bin, and you will have finished compost in weeks. Yes, weeks—not years. And it'll be hot compost—the best kind for plant disease prevention. (But you can't compost grass clippings alone; they just make a big stinky mess.)

No matter what, don't start mowing this season with an old blade. Dull blades don't perform 'mulching' chores well—and they rip the clippings rather than cut them cleanly, giving the lawn a ragged look. Replace the blade (new blades for my mower cost a mere $18 apiece) or have the old one sharpened; you'll see the difference.

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