What Causes Brown Spots in the Lawn – Reasons & How to Fix

What Causes Brown Spots in the Lawn - Reasons & How to Fix
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Brown lawn patches can be upsetting, particularly if you’ve put your time and hopes into creating a stunning carpet of lush, green grass.

Brown spots in the lawn can be caused by high temperatures and humidity, too much nitrogen, and moisture, poor soil damage, too much thatch, and compacted soil.

The most frequent reasons why your lawn develops brown spots are listed below, along with suggestions for how to fix them.

What Causes Brown Spots in Grass?

What Causes Brown Spots in the Lawn - Reasons & How to Fix

You must first identify the exact cause of brown spots in order to combat them. There are numerous causes of brown spots, and each one requires a unique approach to treatment.


Grubs are white beetle larvae that are large and chubby. By consuming roots, they can cause significant damage below ground. Their feeding habits can cause your grass to develop uniform, sponge-like brown spots. Introducing helpful nematodes or milky spore are just two examples of natural, at-home treatments for grubs. Thankfully, grub control is offered by lawn care companies like TruGreen, so you can avoid making any educated guesses.

Brown Patch Disease

Rhizoctonia is a fungus that causes brown patch disease. When it’s hot and muggy outside, particularly in the middle to end of summer, this disease results in patches of dead or brown grass.

What Causes Brown Spots in the Lawn - Reasons & How to Fix

Your lawn will develop irregular brown patches that are yellowish-brown in color and have a smoke ring border. Typically, the grass along the smoke ring border just gets thinner. The grass inside the ring, however, occasionally dies completely. Fortunately, grass that merely thins out can regrow without the use of chemicals.

Your lawn may become brown patchy for a variety of reasons, including extreme heat and humidity, an abundance of nitrogen, moisture, poor soil damage, an excessive amount of thatch, and compacted soil. Given that you can’t control the weather, in some cases, you can’t stop your lawn from getting Brown thatch. But you can take some steps to make it less likely:

What Causes Brown Spots in the Lawn - Reasons & How to Fix
  • Apply fungicide: Even though the majority of lawns recover without chemical assistance, there are some situations where you may need to use chemicals to combat Brown patch. It is best to leave this to experts. At various times, the effects of various fungicides will become apparent. Improvement might be noticeable for some people in just a day or two.
  • Water properly: Watering your lawn early in the morning, before 10 a.m., will help prevent Brown patch, which can result from too much moisture., or between 4 p.m. and 6 p.m. to ensure that the grass dries out fully before nightfall. Your grass will be more vulnerable to disease and pests if you leave it wet all night.
  • Fertilize carefully: Brown patch can be caused by an excess of nitrogen. When it’s hot and humid outside, try to avoid fertilizing your lawn. Also, choose a fertilizer with a good NPK value. NPK stands for nitrogen, phosphorus, and potassium ratios in fertilizer. Inquire at your neighborhood garden center about the best fertilizer for your lawn.
  • Improve air circulation in your soil: Brown patch development will be less likely due to aeration and dethatching, which will lower the amount of humidity. Aerating is done using a core aerator or spike aerator, either pulling many little plugs or “cores” of soil out of the ground, or perforating it with many small holes. With the aid of a dethatching rake, an organic layer that could smother grass is removed. Aeration and dethatching make it simpler for the grassroots to get the water, air, and nutrients they require.


What Causes Brown Spots in the Lawn - Reasons & How to Fix

In between grass blades and the root system, there is an accumulation of organic material that is dead and decomposing. A thin layer of thatch can be beneficial, but one that is more than ½ inch thick can choke the grass by obstructing the supply of nutrients, water, and air, as well as increase the risk of pests and diseases on your lawn.

Dethatching or lawn aeration will help you resolve this problem. A dethatching rake, which you can either rent or purchase from your neighborhood garden store, can be used to remove the layer from your lawn. Check to see if the settings are right for the type of grass you have.

Aerating your lawn entails making numerous tiny holes in the soil to allow it to breathe. A core aerator is the most widely used type of aerator and is one of several that can be bought or rented. To allow for the flow of nutrients, water, and air into your soil, this kind of aerator removes tiny plugs of soil.

Improper Mowing

If your mower’s blades are worn out, they will tear up your grass rather than cutting it precisely. It will die and develop brown spots if the grass is torn or damaged. Sharpening your mower blades in the spring and fall will help you avoid this.

Scalping is yet another problem. Even if your mower’s blades are razor-sharp, you still run the risk of damaging your lawn if you shorten the grass too much. Raising the mower’s blades will help you cut only a third of the grass blades at once.

Too Much Fertilizer

Unwelcome brown spots can be caused by too much nitrogen. Don’t overfeed your lawn by fertilizing it more frequently than is necessary, and avoid fertilizing on hot days.

Poor Soil Quality

What Causes Brown Spots in the Lawn - Reasons & How to Fix

Brown, bare patches could be caused by poor soil quality. Attempt to penetrate your soil six inches deep with a long-head screwdriver. In order to add beneficial organic matter, aerate the area and top-dress it if you encounter too much resistance.

Soil Erosion

Aerating the soil will help you stop soil erosion, increase water absorption, and keep your grass from drying out.

Pet Urine Burns

Because dog urine contains a lot of nitrogen, it can cause brown patches on your lawn. The centers of these brown spots are encircled by dark rings. The best way to fix this is to spread some grass seeds after raking up as much of the patchy areas as you can, covering them with topsoil. To encourage growth, water the area every day for two weeks.


Once it goes dormant, your grass will turn brown. In the winter, warm-season grasses go dormant, and some cool-season grasses might as well. Some areas of your lawn that are made up of various types of grass and are in a transition zone may turn brown before others.

How to Rid of Brown Patches in My Lawn?

1. Water on Schedule

Brown patch, which happens when the surface is wet but the soil is dry, is more likely to appear on lawns that receive excessive watering. Water deeply—roughly half an inch per session—once every three to four days is the ideal schedule.

The best time to water your lawn is in the morning, before the sun comes up too strong and traps the moisture at the surface during the hottest part of the day.

Try to water your lawn between 5:00 and 6:00 a.m. and 9:00 a.m. Avoid watering at night when the grass won’t have enough time to fully cool until the early dawn, despite how appealing it might seem to do so on weekdays after work.

2. Mow High

Due to how quickly your lawn grows in the summer, it can be tempting to cut it short. However, if your grass becomes overgrown, the sun won’t be able to penetrate the top and disperse heat and moisture. (Read More: How Often Should You Mow Your Lawn – Tips & Suggestions)

3. Reduce Heavy Thatch

Did you know that brown patches can develop on a lawn if the thatch layer is too thick? In addition to giving rise to fungi, it also prevents the soil from absorbing water and transferring it to the roots. (Read More: Pros and Cons of Dethatching Lawn – Things You May Not Know)

Aerate your lawn in the early or late fall to help reduce thatch. To allow the soil to absorb water, the aeration process involves removing countless tiny soil plugs. This will assist in giving your lawn the consistent oxygen, nutrients, and water it requires to look its best.

4. Fertilize Properly

When treating and fertilizing your lawn, it’s important to use the right fertilizer mixture. A brown patch can become stronger than your turf if there is too much nitrogen present because fungus reacts to it in the same way that grass does.

5. Ensure Proper Drainage

All homeowners encounter the issue of compacted soil when attempting to maintain a healthy lawn because it causes poor drainage in the area.

If the blade of a screwdriver is difficult to move into the soil, the soil is compacted. This can be done to check for compacted soil in your grass. This means that your lawn has excess surface moisture because the necessary amounts of water and nutrients are not reaching the grass’s roots in the soil. Your lawn’s most used areas are most likely to become compacted, which will then cause an accumulation of extra surface moisture.

We advise that you aerate your lawn twice a year—once in the spring and once in the fall—to prevent soil compaction.

6. Apply a Fungicide

On the affected areas of your lawn, you might want to use a fungicide for quick results. If applied correctly, the use of the products can produce more immediate results and will be most effective at the earliest signs of brown patch fungus.

The fungicide you select will largely depend on what is available to you in your area and which type of application will be most effective for you as a homeowner. The majority of fungicides need to be applied twice a month, but before using one, make sure to read the packaging and instructions to ensure proper and efficient application.

7. Maintain a Healthy Lawn

It will be simpler to prevent brown patches if your lawn is healthier in the beginning. Give your grass the vitamins, protection, and regular watering, mowing, fertilizing, and weed control that it requires to thrive all year long.

It might be in your best interest to hire a reputable local lawn care company to take care of it for you throughout the entire year if you’re busy with work, family, and house maintenance.


In order to establish and maintain a healthy turf that is less prone to brown patch, it is best to hire a professional local lawn care company. They can take care of soil aeration, disease control, moisture retention, de-thatching, and other tasks for you throughout the year.


Why is My Lawn Turning Brown in Spots?

Grass plants have been known to begin growing roots higher in the thatch layer when thatch buildup is high. The plants start to dry out as a result of that layer’s inability to retain water, which results in brown patches on the lawn.

What is the Best Fungicide for Brown Patches?

An excellent option for preventing brown patch is Headway fungicide. Azoxystrobin and propiconazole, the active ingredients in Headway, provide broad-spectrum control of all common turf diseases, including brown patch.

What Fungicide to Use for Brown Spot Lawn?

In general, brown and large patches can be controlled for 28 days with azoxystrobin, pyraclostrobin, or fluxastrobin. The disease will be under control for 14 days thanks to the other three fungicides.

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