If brown patches suddenly pop up in your lawn in the middle of summer, the most likely culprit is a fungal disease called, “brown patch.” Grass turns brown when it’s no longer receiving the proper nutrients, so this could be caused by the disease, underwatering, overwatering, or overfertilization.

Brown patches may occur for different reasons, so it is essential to consider the context before making a diagnosis. Once you have made the right diagnosis, you will be able to apply a fix and take steps to avoid the problem in the future.

Learn what brown patch is, what other culprits can cause brown patches in a lawn, and how to make those unsightly brown patches in your lawn disappear.

Why Brown Patches Appear in Your Lawn

Not every brown patch you see in your lawn is due to the fungal disease of the same name. This is why you need to consider factors such as where you live and what time of year it is before taking action.

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Brown Patch Disease

This fungal disease is a common lawn disease and attacks cool-season grasses. These types of grasses include Kentucky bluegrass and fescue.

Brown patch actually starts out by turning patches of your grass yellow. This will typically happen on an especially hot, humid night in summer during periods of excessive rainfall (fungal diseases love moisture).

Your chances of getting brown patch under these conditions increase further if you have recently applied a high-nitrogen fertilizer to the lawn.

Improper Watering

In watering a lawn, it is necessary to keep a delicate balance between overwatering it and underwatering it. The soil underneath your grass should be evenly moist: it should be neither soggy nor dry. Both overwatering and underwatering can lead to brown patches in your lawn.

Pest Issues

Various insects attack turfgrasses. You may not see them at work, because they may be feeding on the roots of your grass. These attacks can cause the grass to die in places, leading to the formation of brown patches.

Animal Urine

Dog urine can kill grass, causing brown patches. This fact leads some homeowners to use repellents to keep stray dogs off their lawns. But if you have a dog, yourself and you allow it to play on the lawn, you may end up with brown patches.

Chemical Burn

Always be cautious when using chemicals on the lawn, whether it be chemical pesticides, herbicides, or fertilizers. Applying a chemical in excess to the lawn (or, worse yet, accidentally spilling a chemical somewhere on your grass) can burn it and cause brown patches.

5 Fixes for Brown Patches in Your Lawn

Fortunately, there are simple fixes for brown patches in your lawn.

• If you have an infestation of the brown patch fungus, remove the grass already killed by it so that the fungus does not spread. Reseed the areas where you removed the dead grass, and apply a fungicide to the lawn as a preventive measure.
• If improper watering caused the problem, pay attention to how long and how often you are watering your lawn.
• If you detect a major infestation of pests in your lawn, you will need to apply a pesticide and reseed areas where the grass died.
• If the brown patches in your lawn are the result of dogs or other animals urinating on your grass, apply a blast of water to the affected area with your garden hose as soon as you see the urination taking place. The water will dilute the urine and minimize its impact.
• Always exercise moderation when using chemicals on the lawn. For example, when using chemical fertilizers, apply half the recommended amount when in doubt. If an accidental chemical spill kills your grass somewhere, you will have to reseed that area.

How to Maintain Your Lawn and Avoid Brown Patches

With proper care of your grass, you can usually achieve a lawn healthy enough to avoid developing brown patches; this is routine grass care that, as a bonus, helps you avoid brown patches. Examples include:

• Furnishing good drainage
• Keeping the soil evenly moist
• Allowing the grass blades to dry out (thereby depriving fungi of moisture) by watering in the morning
• Feeding your lawn properly, on a regular schedule (but avoiding high-nitrogen applications in mid-summer)
• Staying ahead of problems caused by pets and pests

In addition to routine grass care, you can take a special step to avoid the brown patch fungus during the time of year when grass is most susceptible to this disease: Mow the lawn more often than you typically do. By keeping the grass from getting tall, you improve air flow through the lawn, which is a great way to fight fungal diseases.