Not WD-40 Or Oil: The Mowing Pattern That Keeps Grass From Clumping On Your Lawn Mower

Nothing ruins the look of a freshly mowed lawn quite like realizing that instead of perfect stripes, you've left behind clumpy rows. Regular mowing is one of the keys to a lush green yard, but if you aren't using the right pattern, grass can quickly clog up your lawnmower deck and chute before being scattered everywhere. If you've ever asked, "Why does my grass clump when I mow?" you're definitely not alone. To find out, we asked Bryan Clayton, CEO of GreenPal, to explain why those clumps happen in the first place and how to avoid them using a crisscross mowing pattern. 

According to the lawn care expert, there are a few common culprits. "The clumping is happening when you're mowing [when it's] too wet, or you let the grass grow over 3 inches tall," Clayton told Hunker during an exclusive interview. A heavy rain or sprinkler session makes your lawn look great because water makes each blade of grass plump up, but that wet grass is also heavier and stickier when it's being sliced by your mower blades. 

Things can also go from bad to worse when the grass is also too tall. "Your lawnmower can't handle the excess lawn clippings," Clayton explained. These factors lead to buildup under your mower's deck, where fresh-cut grass hangs out until it's a clumpy mess that gets randomly deposited instead of smoothly dispersed. According to Clayton, "The best way to deal with that is to mow every six days and to only mow when it's dry."

If you're plagued by clumping grass, everyone from your next-door neighbor to that random guy at the hardware store has probably offered you simple tips for a lawn mower deck that keeps getting clogged. Instead of spraying it with WD-40 or oil, Bryan Clayton has another suggestion. "Alternating the pattern on mowing your yard is a really good idea. The reason is because it spreads out the stress caused to your turf by your mower's tires or wheels," he explained.

Along with creating a nice visual effect, using alternating directions every time you mow encourages your grass to grow upright and prevents soil compaction. It can also help you avoid creating ruts in your yard that lead to brown patches of grass, bad drainage issues, or both. "The tires can cause damage to your turf, especially when you're turning," Clayton said. "So if you alternate patterns like a crisscross every week or every other week, it can help spread that stress over the yard."

However, to keep grass from clumping on your lawn mower, the expert said you'll need to use the pattern every time you mow. He recommends using one angle on the first pass and crisscrossing on the second pass, on the same mowing. "That second pass from a different angle helps disperse the clippings better [and] it helps with clumping," Clayton explained. But if you only switch directions each week, he says you'll probably still experience the same clumping issues.

Using a crisscross mowing pattern is one way to help keep grass from clumping on your lawn mower. But Bryan Clayton has another tip that may help if you feel like you spend more time cleaning your lawn mower deck than you do actually mowing the lawn. "It's a good idea if you're dealing with grass that's over 3 inches tall to mow with half the deck," he said. 

In other words, instead of making each pass with the entire deck and sending a bunch of tall grass through your mower at once, overlap your passes so that only about half of the deck is cutting fresh grass at a time. This can reduce the amount of clippings the mower has to process, which may help prevent them from piling up underneath your mower or along your lawn.

"Let's say you have a riding lawnmower with a 42-inch deck. You can just use 20 inches of the deck to do the mowing, and the other horsepower from your lawnmower and deck can handle the clippings," Clayton explained. The lawn care expert added that this approach won't be necessary if you stay on a weekly mowing schedule, but that it's a great option if you've let your yard get out of control. This strategy, combined with a crisscross pattern, can eliminate clumping on your mower deck.