How Often Should I Replace Lawn Mower Blades?

If you already mow your lawn regularly, chances are that you know how critical this practice is to keeping your grass healthy. Yet the health of your lawn requires much more than mowing it regularly. Using a well maintained lawn mower also makes a difference. To that end, a common question is, how often should you replace your lawn mower blades? The general rule says you should replace them once a year or more, but you may need to do this more or less frequently depending on your own situation.

A lawn mower blade needs regular replacement in order to cut your grass more efficiently. Both the North Dakota State University Extension and University of Maryland Extension recommend doing so at least once a year. Overall, the exact amount of time you should go in between lawn mower blade replacements depends on how often you mow your lawn, as well as its square footage. Mowing frequently and/or cutting a large lawn are both logical reasons why you might have to replace your lawn mower blade more often than someone who doesn't mow as often or who might have a smaller yard. Yet another reason is the type of grass, as some have exceptionally fast growth rates during the summer growing season. Bermudagrass is one notable example, and it's a coarse grass type that may also require mowing twice a week or more often during warm weather, says Mississippi State University Extension.

At the same time, the once-a-year rule for changing your lawn mower blade isn't really set in stone. Aside from mowing frequency, there are other situations that could warrant a replacement. If you notice that your grass blades look uneven or damaged instead of sliced clean after mowing, these could be signs your blade is bent or dull. Any unusual noises during mowing are also worth pausing for – these can be related to a damaged blade, or perhaps something more dangerous. Upon closer inspection of the equipment, you might see that the blade itself is bent, dented, cracked or even cracked.

On the other hand, if your lawn mower blade appears to be in good shape but the grass looks uneven after mowing, chances are you may just need to sharpen the blade. Aside from a more even turf, a sharp lawn mower blade slices the grass blades in clean cuts, which reduces the risk of diseases and sun damage that can develop in grasses torn by dull blades. As with the blade replacement, the exact sharpening schedule depends on mowing frequency as well as the size of your lawn. Some people need to do this at the beginning of the growing season every year at minimum, while others don't need to sharpen their lawn mower blades so often. When in doubt over whether your lawn mower blade needs sharpening or a full replacement, consider taking the equipment to a reputable mechanic. Maintaining this important piece of lawn equipment regularly not only keeps your grass happy, but it will also extend the lifespan of the mower, too.