Why Is My Grass Turning Yellow?

Are you stepping outside to a lawn that’s less green and more…yellow? It might feel disheartening, especially when you’ve been putting in the effort to keep your outdoor space looking its best.

But don’t worry. You’re not alone in this. Many homeowners face the challenge of yellowing grass. And the good news is, there’s usually a solution right at your fingertips.

Learn how to transform your yellowing grass back to its vibrant green glory with this guide from Blain’s Farm & Fleet.

Poor Soil

If you have soil that’s badly compacted, has poor pH, or is lacking nutrients your grass needs to grow and stay strong, you’ll need to aerate and fertilize your lawn.

To tell if your soil is badly compacted, stick a long screwdriver into the problem spot. If it’s hard to penetrate the soil, your soil is too compacted, and you’ll need to aerate it.

To check the fertility and pH of your soil, use a soil tester kit or probe. If it reads low fertility, you’ll need to apply fertilizer. If the pH is over 7, you need to treat your lawn with a sulfur fertilizer or a soil acidifier. If the pH is below 5.5, you’ll need to apply lime.

This is one of the lawn problems that’s easy to fix with the right tools and treatments.

Drought or Heat

If your entire lawn (or most of it) is yellow or brown, you should suspect heat or drought. Both of these problems are actually the same—not enough water is getting to the roots of your grass.

In very hot weather, the sun can evaporate most of the moisture from rain and light watering before it’s had enough time to soak into the soil around the roots of your grass. The way to reverse this is to water more during hot spells.

For better long-term protection against heat and drought, use a fertilizer mix with high phosphorous and potassium levels. This will strengthen your lawn and help it grow deeper roots, which will allow it to resist lawn problems like drought and heat in the future.

Insects

If your soil looks good and lack of water isn’t the problem, it’s time to get down and inspect your lawn with a magnifying glass. If you see any holes or brown, yellow, or orange spots on the blades of your grass, you may have an insect infestation.

Also, check the dirt between your grass blades for small holes or insect eggs. Insects can damage your grass by chewing and eating the blades or roots.

If you discover bugs, treat your lawn with an insecticide. After the treatment, your lawn should be back to normal. Long term, you may want to use a fertilizer with bug control to prevent the critter lawn problems from coming back.

Improper Mowing

Improper mowing can damage your grass and eventually kill it. Good mowing habits can improve your lawn problems a lot.

Cutting Too Short: If you cut your grass too short, it’s not able to absorb enough sunlight to grow and stay healthy like it should. Increase the cut height on your mower to fix this problem.

Scalping: If you have a bumpy lawn, your grass probably gets scalped on those bumps. This is one of the easiest lawn problems to spot.

If your yellow or brown spots are all on bumps or ridges in your lawn, you’re probably scalping it and need to increase the cut height when you mow.

Dull Mower Blades: Dull mower blades rip the grass instead of cleanly cutting it. They also tug the grass up with every pass and damage the roots.

Be sure to sharpen your mower blades regularly. You can do this yourself, or have one of the small engine service mechanics at Blain’s Farm & Fleet do it for you.

Disease

This is where you’ll probably need a professional landscaper to inspect your lawn. There are hundreds of different plant diseases that can infect your lawn. They can be caused by pollution, fungus, and insects.

Once your landscaper finds which disease your lawn has, they will recommend an appropriate treatment. If your lawn has a fungal disease, you can prevent it from coming back by using fungicides after you get rid of it.

Pet, Animal, and Other Damage

Animal Urine or Grazing: Animals can contribute to yellowing lawns in a few ways. Dog urine and other animal urine contains very high levels of nitrogen, which can burn grass.

Similar to cutting your lawn too short, animals can also bite off too much of the blade. This can prevent your grass from absorbing enough sunlight. And the tugging damages the roots.

The solution to both of these problems is to install a fence to keep animals out of your yard. Or if your pet is responsible, you’ll have to train them to do their duty somewhere other than on the lawn. Some homeowners install a gravel patch in their yard for a pet toilet.

Chemicals: Any spilled chemical can damage or kill your grass. This is because grass roots will soak up virtually any liquid, even if it’s toxic. Applying too much fertilizer or spreading it unevenly can cause brown or yellow spots, as well. So can using the wrong herbicides to fight weeds.

You may need a professional soil test done to diagnose this problem. The fix is to never pour any chemicals on your lawn, and to use fertilizers carefully.

Also, if you have badly-polluted spots where your grass has died and you can’t get new grass to take root there, the soil may still be polluted. You might have to call a professional landscaper to dig the polluted soil out and replace it with healthy soil.

Buried Objects: Buried objects can prevent the grass planted over them from developing healthy roots. Probe any brown or yellow spots in your lawn with a long screwdriver to makes sure there’s nothing buried under the grass.

For more tips like these, check out our other Lawn Care articles.