The International Lawn, Garden and Power Equipment Expo in Louisville, Kentucky, is a motor-head's dream. This annual event fills a 250,000-square-foot convention center and arena with mowers, tillers, chain saws, edge trimmers and every kind of garden tool you can imagine. And there's another 500,000 square feet of displays outdoors under tents. That's more than 17 acres! There are flourishing farms that are smaller.
The Expo is where landscapers, retailers and even some gardeners come to kick the tires, grip the handlebars and take the latest models out for a test drive. The outdoor area is set up for hands-on demonstrations where you can mow and till and shred to your heart's delight.
Mowers were the order of business last year -- mulching mowers. Virtually all of the mower companies were touting their new lines of mulchers. In fact, it was hard to find a mower that wasn't a mulcher. Somehow, when I wasn't looking, the mulchers took over. Everywhere, there were shiny new mowers sporting names like the Tricycler, Harmony, Re-Cyler, LawnCycler and Mulchinator (if that machine veers off into the ground cover, it's time to say: "Hosta la vista, baby").
These mulchers that have roared onto the scene are a mystery to many. So I did my best to find the answers to some commonly asked questions.
Why mulchers? Why now? This seems to be a case of a happy convergence of technology, marketing, capitalism, environmental concern and sound landscape practices. Mower manufacturers have been fiddling with the mulching concept since the 60s, but recent legislation throughout the country that prevents homeowners from sending grass clippings to the landfill has given the industry a big boost. Homeowners have to figure out somewhere to put the clippings, and there's no doubt that the best place is back on the lawn (unless it's on the compost pile). Are mulchers good for the lawn? Absolutely. You can forget all the fears about clippings causing harmful thatch. Clippings are not the main ingredient of thatch because they break down quickly and start providing nitrogen to the soil within a week. Thatch is mainly made up of roots, stolons and rhizomes (the above- and below-ground "runners"). These plant parts are high in lignin, making them slow to decompose. Using a mulching mower may actually lessen the severity of thatch. By adding that organic matter and nitrogen, microorganism activity is encouraged, and that helps to break down thatch.
There's no question that not removing the clippings makes the lawn healthier. When clippings are left, they contribute nearly two pounds of nitrogen per 1,000 square feet per year -- just about enough to keep a lawn growing vigorously.
Of course, you don't need a mulcher to leave the clippings on the lawn. And as long as you follow the one-third rule -- never cutting more than one-third the height of the grass blades at any one time -- the clippings break down just fine. (In fact, tests show that nitrogen from clippings begins showing up in the blades within a week.) But a good mulching mower minces clippings into tiny particles and blows them back down to the soil level, where they break down even faster.
How do mulchers work?
Today's mulching mowers are more than side-discharge mowers with the chute blocked off. The difference is obvious even when you look "under the hood." Most mulchers sport a characteristic donut- shaped deck housing. While mowing, air currents swirl within, lifting the clippings so they can be cut again by the blades, then forcing them down into the turf.
And what about those blades? Suddenly they aren't so straightforward anymore. These days they come in as many shapes and sizes as razor blades. There are twin blades, quad-blades, single blades, split blades and notched blades. How does one choose? Engineers are working feverishly to design blades that chop the grass into smaller and smaller pieces. It's true that the smaller the clippings are, the faster they break down and disappear. But in the grand scheme of things, it probably doesn't matter much whether the clippings are 1/8 inch long or 1/16 inch. What's more important is how you use the mower.
How do I use a mulching mower? "What's this I hear about mowing more often?" you ask. It's true. Mulching mowers don't require that you learn the art of mowing all over again, but they are a bit more demanding. For example, a mulcher won't work properly if you're cutting off more than 1 1/2 inches of growth. (You really shouldn't be cutting off any more than that, regardless of the type of mower you're using. But a mulcher will force you to use good mowing techniques and obey that one-third rule.) Some manufacturers say that mulchers work best when you're cutting only the top 1/2 inch. That means you may have to mow more frequently than you're used to, perhaps as often as every third day.
When using a mulcher, it's most important to vary your mowing pattern occasionally. If you mow in an up-and-back pattern time after time, windrows of clippings will build up along your path. To ensure that the turbulent airflow is working properly, it's important to keep the deck clean. Scrape out any matted cuttings after each use. Hose it down. Keep the blades sharp.
What should I look for in a mulching mower?
Look for a deck that is smooth and rust resistant (inside as well as out) to discourage clippings from building up "under the hood." Mulching mowers need a little more power than the traditional ones, so make sure you get at least a 4 1/2 hp engine. Look for a mower that adjusts easily to a full range of cutting heights, up to four inches.
If you do sometimes use your clippings for mulch or in the compost pile, or if you're occasionally late in mowing your lawn, choose a mulcher than can convert to a side-discharge or bagger type.
If you're concerned about noise, pollution or the price of gasoline, consider an electric mower. One of the stars of last year's show was a rechargeable electric mulcher. It will mow for up to one hour on a single charge and can be recharged in 16 hours.
Are mulchers right for everyone?
You probably shouldn't buy a mulching mower if you're a repeat offender of the rule of one-third -- someone with a casual mowing schedule whose lawn gets long and shaggy between cuttings. When a mulching mower is used on grass that's too tall, or too wet the clippings clump up and lie on top of the grass canopy. They can even build up under the deck and cause stalling or rough running.
You shouldn't buy a mulcher if you like to race across the lawn with the mower. Mulchers need to take it a bit slower than regular mowers because they need to allow time for the grass to be cut twice. Compared with using a bagger, however, mowing with a mulcher may still take you less time because you don't have to stop to empty the bag.
A mulcher is not for you if you regularly use your grass clippings for compost or mulch. Mulchers grind up the clippings so small that you probably couldn't find them if you wanted to.
But if you're fairly faithful in mowing your lawn, if you believe clippings should be out of sight and out of mind, and if you want a better-looking lawn without additional fertilizer, then a mulching mower makes sense.
Warren Schultz is editor in chief of National Gardening.
Copyright NGA
Reprinted with permission HouseNet, Inc.
Mulch ado about mowing
by Warren Schultz