Mysterious patches of burnt-looking brown grass in your lawn can be frustrating to fix if you can't stop them at the source. There are several culprits that can cause burnt spots in lawns, including maintenance problems, extreme weather, insects, disease or even your neighbor's dog. Most of the time, burnt spots are the result of several of these problems working together to damage your lawn.
If your lawn has suddenly developed round brown patches surrounded by a narrow swatch of exceptionally green grass, dogs may be your problem. Dog urine is a concentrated source of nitrogen that can damage your lawn. The only 100-percent effective way to prevent this kind of damage is to keep the offending animal off your lawn through fencing or training. In most cases this kind of damage is mild and will go away on its own.
Spilling gasoline on the ground while you are fueling up a lawnmower is easy to do, but it can cause burnt patches in your lawn. Ensure that you fuel up your lawn equipment over pavement and use a funnel to prevent spills. Improperly applied fertilizers can also damage your lawn, leaving burnt-looking streaks or patches. If you plan on applying fertilizer to your lawn, make sure that you don't apply too much, and never apply fertilizer to wet grass.
A low-cut lawn has an appealing look, but cutting your grass close to the ground is a constant burden on its health. Lawns that are regularly cut low often develop shallow root systems that are vulnerable to damage during warm weather. If brown patches are appearing on the lawn during warm summer weather, water your lawn more deeply and allow it to grow a little taller. This will allow your lawn to recover and help it grow more resistant to high temperatures in the future.
Using the right mowing techniques, you can improve the health of your lawn and prevent burnt-looking spots that appear after mowing. One common cause of burnt spots in lawns is dull lawn mower blades. If the blades of grass in your lawn look jagged and torn after mowing, it is time to sharpen your mower blades.
Gaps in your irrigation system, drainage issues or excessive thatch can prevent your grass from getting the water it needs. You can check burnt spots for dehydration by stabbing a screwdriver into the ground at the burnt spot and in the surrounding soil. If the soil in the burnt spot is significantly drier than the surrounding soil, dehydration is the issue. You can use a dirt rake to remove excessive thatch from burnt spots.