10 Signs You Need to Check Your Lawn Mower Blade Sharpness

Notice your lawn looking a little uneven? That could be a sign it's time to sharpen your lawn mower blade.

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Turf grass close-up
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Uneven Grass Height

An uneven lawn is an obvious sign something might be off with your lawn mower blade. If fixing the alignment or tightening it doesn’t work, it might be time to sharpen the blade.

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Mowing Areas Multiple Times

A dull mower blade can force you to make several passes in the same area. If this happens routinely, that’s an obvious sign to sharpen or replace the blade.

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It’s Taking Longer to Mow

Longer mow times may not mean you’re out of shape or dawdling in the yard. It could be your mower isn’t moving as swiftly through the grass as it used to. Here are some tips to make sure you’re mowing the most efficient way.

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RoundUpRelief LawnMower

You Need to Push the Mower Harder

For push or walk-behind mower owners, dull blades can turn simple lawn care into a full-blown workout. Check the sharpness of your blades if mowing the lawn becomes more strenuous.

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Torn, Not Sliced, Grass Blades

Sharp mower blades cut grass evenly. Dull blades won’t give you that clean yard look. You can learn a lot by examining the cut of your grass blades. Is the mower properly cutting the grass or yanking it out of the ground? Jagged tips mean it’s time for a sharpened blade.

Pro tip: Use the Sharpal Knife Sharpener to sharpen dull blades in a flash.

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Clogged Mower Deck Gettyimages 1293643150
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The Blade is Dented or Bent

Sometimes the easiest way to tell if there’s a mower blade issue is looking at the blade itself. Blades can get damaged over time. If there are any sizable dents or if the blade is bent, it needs to be sharpened or completely replaced.

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Frequent Stalling

A wide range of issues can cause a lawn mower to stall. Here’s one: Dull blades that force the engine to overwork. If the mower stalls through thick grass areas, try sharpening the blade to see if that fixes the problem.

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Grow Greener Grass thick grass growing tips
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Discolored Lawn

A mower with a dull blade can leave yellow or brown patches on your lawn, leaving it susceptible to diseases.

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Grassy weeds
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Blade Pulls Up Chucks of Grass or Dirt

Rather than cleanly slicing through grass, a dull blade can not only pull clumps of grass from your lawn, but some dirt as well. The blade should always slice the grass, not pull.

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Mower blade
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It’s Been Awhile

Lawn mower blades should be sharpened every 20 to 25 hours of use time, according The Home Depot. If you’d rather not sharpen the blade, they’re not overly expensive to replace.

Alex Shoemaker
Alex Shoemaker is a Florida-based journalist and  handyman who has extensive experience in home remodeling and house flipping.