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8 Main Reasons Why Your Lawn Mower Leave Lines

8 Main Reasons Why Your Lawn Mower Leave Lines

Do you ever set out to cut your lawn, everything is going smoothly. The blades are slicing through the grass blades like they’re not even there. The sun is shining.

You’ve got your favorite music playing. Then you turn around only to find your garden resembles a monopoly playing board rather than a beautifully cut lawn? If you don’t follow some specific rituals or checks before you cut your lawn, then you can end up with a problem like this.

If only I had a dollar for every time this had happened to me. I would spend hours in the bearing sun, cutting the lawn as precisely as I possibly could, only to leave those horizontal lines all over the place.

It was a disaster. That was until I learned these 8 causes why my lawnmower was leaving those ugly horizontal lines. Today, I am going to share them with you. I will even offer some free tips on how you can make sure that next time you can mow your lawn completely free of any lines.

Ready to dive right in? Let’s get started.

1. You are mowing your lawn too quickly.

You are mowing your lawn too quickly

The first reason, and perhaps the most common of them all, is that you are mowing your lawn too quickly. Uncut lines can arise when you are mowing too quickly, since the engine is forced to work harder, maximizing its own throttle.

Engine problems can be the root of several gardening issues. The solution is just as simple as the problem itself: Go slower! Take your time. Don’t let the engine operate at full throttle and you’ll find you won’t leave any lines as a result.

2. You aren’t overlapping on the rows.

Again, another common error when mowing the lawn. You always must make sure that you aren’t leaving a little bit of space in between the columns you mow. If you don’t leave a gap, the mower’s blades will pull upwards and the tires will press downwards, which is what creates the lines in the grass.

Again, you can’t just mow the edge of the rows you just previously cut. You must make sure that you spare a couple of inches on the row before so that you can cut the line your tire just mowed on. Failing to do so will just make the lines you created even deeper than they were before.

3. Your blades are too small.

Your blades are too small

This issue is most common for gardeners who have bought new blades or sent their mower away to have the blade on it replaced. So, if your lawnmower worked fine for years, then after you replaced the blades, it started to show these issues, then the blades might be too short for your lawnmower.

I mean the reason why this causes lines is simple. If your blades are too small, then they won’t be able to reach all the way across and cut the whole row you are mowing. This leaves small gaps in between each row that you cut.

4. Your blades are too blunt.

This issue will normally affect people who use self-propelled lawnmowers. If you notice lines in your lawn after you mow it, you should check to ensure that your blades are sufficiently sharp for cutting. To make sure that your blades are suitable, you should sharpen them between once and twice per season.

Oh, and by the way, blunt blades can cause other problems, too. They can damage your grass, and they may be what leaves the jagged yellow tips after you mow your grass. Follow the above procedures to avoid this kind of problem.

5. Your engine settings are wrong.

Your engine settings are wrong

Sometimes, your lawnmower might leave lines because of engine performance. Like we mentioned in the first point, you have to make sure that your engine is not being pushed too hard.

You can always adjust the engine settings by yourself, you won’t need the help of an expert or professional. You can do this by adjusting the throttle cable. When leaving your lawnmower engine on a higher speed setting, you will notice that lines can arise after mowing.

6. You’ve got fuel problems.

Again, tying in with the last point on engine performance. If your fuel quality isn’t up to scratch, then the performance of your lawnmower will reflect that.

If you want to avoid leaving lines, then try to avoid using fuel from the previous season. It can lose quality after even more than 4 weeks inside the carburetor of the engine.

This causes the fuel to gum up and get stuck in the engine which reduces the overall smoothness and performance of the engine. The result being a sluggish display, leading to those dreaded lines in your garden.

7. You’ve got some other kind of problem with your blades.

So, we’ve already talked about having blunt blades and blades that are too small. But they aren’t the only issues that can lead to poor cutting.

If you notice lines in your garden, you should check to make sure that your blades aren’t curled, warped, or defective in any other way at all. The only real way to fix this issue, is to get your blades checked, and replaced if needed.

It isn’t uncommon to have blades that are the wrong way around or disorientated in any other way. But don’t worry, because this is the exact kind of issue that you can solve yourself, no real expertise needed. Oh, and if you’re asking yourself, ‘how on earth do I do that?’ that’s right, we have got you covered.

8. You’re doing something else wrong.

You’re doing something else wrong

So if you have read through the list, and nothing seems to ring a bell, then this last option might be for you. Try the following options if you’re still getting lines on your grass when you cut your lawn.

  • You have the engine running at a below optimum speed. Like we mentioned before in point 5, you need to make sure that your engine is at optimal settings, and that you’re mowing at an adequate speed to avoid a poor cutting performance.
  • Your tire pressures are wrong. If you have tires that are uneven, or too heavily inflated in general, then you need to make sure that they are at the optimum pressure setting. Failing to do so will leave the dreaded lines pattern on your garden lawn.
  • Additionally, make sure that your lawnmower doesn’t have a floating deck, and turn slowly at corners to make sure that you don’t have any missed grass spots when you are mowing your lawn.

What to do about your lawnmower leaving lines in the grass.

Well, there you have it, the 8 most common reasons why there are lines in your lawn after you mow. The solution to solving them, is simple, you just have to make sure that you take care of your blades and cutting technique outlined above.

Additionally, you have to make sure that your lawnmower is of sufficient quality. If you are using a cheap and/or old lawnmower, then the quality of your grass cuttings is going to reflect that. No amount of gardening technique can make up for poor equipment. Always make sure that your lawnmower is of reasonable quality, and get it checked by an expert if you think you have any problems.

But if you still need some additional help on how to avoid leaving lines in the grass when cutting, then check out this awesome video on Youtube, which will tell you a little more about the problem.



In conclusion then, there are a number of reasons why your lawnmower might be leaving lines in it, and we have diagnosed most of those issues in today’s article. If you can take extra care when you next mow your lawn, then you should notice an improvement like this.

It’s not always easy to keep your lawn in perfect condition. It takes maintenance, technique, and hard work too. But the price to pay to get a garden the neighbors will envy is one definitely worth paying. It means you’ll have to go the extra mile in order to keep it in good condition, but that’s what makes it so fun, isn’t it?

Thank you for reading!

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