6 ways to get rid of brown spots in your grass

Key points

• Shade, drainage problems, pH imbalances, overfertilization, pests and diseases can cause brown spots in grass.

• Applying fungicides and pesticides, fixing drainage and improving soil health can eliminate brown spots.

• Maintain a healthy lawn through mowing, watering and fertilizing to prevent new brown spots.

Brown spots on your once-healthy green lawn aren’t just unsightly — they’re often a sign of an underlying condition that requires attention and could put your entire lawn at risk.

Whether it’s a pest infestation, poor soil health or quickly spreading disease, you’ll want to determine the cause of your lawn’s brown spots before starting a treatment plan. Common treatments include applying fungicides and pesticides, fixing drainage and improving soil health. The problem is unlikely to resolve on its own, so don’t put off inspecting your yard.

We spoke with experts Rafi Friedman, president of Coastal Luxury Outdoors in Jacksonville, Florida, and Nicole Carpenter, president of Black Pest Prevention in Charlotte, North Carolina, to help us break down brown spot causes, treatments and preventive practices.

Here’s how to welcome back a vibrant yard with our lawn care tips.

What causes brown spots in grass?

One or several causes may be behind those brown spots dotting your otherwise green lawn. 

“The better question is what isn’t a cause of brown spots in a lawn,” Friedman said. “Brown spots could mean that your lawn is too dry, that it doesn’t have enough drainage, that it hasn’t been dethatched or that you’re dealing with any of a handful of different pests.”

You’ll need to figure out what’s causing your brown patches before you can treat them effectively. Here are some of the most common causes of brown spots in grass.

Excessive shade

Every backyard needs a little shade for late summer lounging, but too much of it can lead to brown spots in your grass.

Shade limits the sunlight reaching your lawn, causing healthy grass blades to lose out on much-needed energy. Over time, this deficiency can weaken your grass and lead to brown spots. Humid weather also causes shaded areas to retain more moisture than sunny spots, increasing the risk of grass developing certain diseases, such as large patch disease.

Poor drainage

Waterlogged soil is a common problem that can suffocate grass roots, leading to rot and brown spots. Excess water from poor drainage can leach essential nutrients from the soil, weakening grass and making it more susceptible to disease.

Poor drainage leads to soil compaction. When soil particles press too closely together, they restrict the free movement of air and water. This can lead to the development of shallow root systems, leaving grass vulnerable to stress and wilting — ultimately resulting in brown spots.

Unfavorable pH levels

If your soil is too acidic or too alkaline, your grass won’t be able to get the nutrients it needs to stay green and thrive. 

Several things can change your soil’s pH, including water quality and excessive fertilizer use. Additionally, fallen leaves, grass clippings and dead plant material can decompose and release acids or bases into your soil, altering pH levels. Even your local climate can change soil pH levels over time.

Too much fertilizer

Fertilizers can make a lawn happy and healthy, but going overboard during an application can have the opposite effect. This result is especially true with fertilizers containing nitrogen. Too much of the nutrient can make your grass grow too fast, leading to weak and shallow roots. As a result, grass becomes more susceptible to diseases, pests and, consequently, brown spots.

Fertilizers also contain salt, which can build up in the soil over time. This creates a harsh environment, making it harder for grass to absorb water and nutrients. Brown spots often develop as the grass struggles to survive.

Troublesome pests

Pests — grubs, chinch bugs and armyworms — feed on grass blades, causing them to turn brown or die off entirely. Other bugs, such as mole crickets, feed on grass roots, making it difficult for the grass to absorb water and nutrients. Leafhoppers can transmit diseases that cause discoloration, while billbugs can contribute to thatch buildup that suffocates grass roots.

Mammal pests, including chipmunks, moles and voles, can invade a lawn, tunnel through soil and damage grass roots. 

Carpenter emphasized the importance of accurately narrowing down the pests. “Dealing with pests causing brown or dead patches on lawns requires identifying the specific signs and damage each pest causes,” she said. “There’s no one-size-fits-all solution.”

She added that while some issues may be resolved with simple adjustments in watering and mowing practices, others may require biological controls or pesticides. Call a pest control specialist if you need help identifying which pests are infesting your lawn. Then, treat the problem accordingly.

Common lawn diseases

Your yard is a living organism and can suffer from several diseases that cause brown grass, including the following:

Brown patch

Brown patch, or large patch, is a common fungal disease that results in circular patches of brown or tan grass, often surrounded by a dark border resembling a smoke ring. It primarily affects the grass’s leaf blades and thrives in warm, humid conditions.

Take-all root rot

Take-all root rot is a fungal disease that infects grass roots, causing them to rot and die. This leads to wilting, yellowing and browning of the grass above ground.

Necrotic ring spot

Necrotic ring spot is a fungal disease characterized by circular or horseshoe-shaped patches of dead or dying grass in a lawn. Unlike brown patch, which affects grass blades, necrotic ring spot primarily affects the roots and crowns of cool-season grasses.

How do you get rid of brown spots in grass?

Bid farewell to an unsightly brown lawn and explore the following grass restoration strategies.

1. Apply a fungicide

If you believe a fungal infection is causing your lawn’s brown spots, a fungicide can help. Fungicides contain chemicals that target and control fungal pathogens.

When applying, follow the manufacturer’s instructions carefully. Pay attention to proper dilution rates, application methods and safety precautions.

Use a sprayer to ensure even coverage of the affected areas, and consider the weather forecast when deciding when to apply fungicides. Ideally, you should apply when it’s hot and humid since this type of weather is more likely to result in disease development.

2. Fix drainage issues

Everyone knows that grass needs water, but when your yard doesn’t allow it to drain properly, your lawn can drown and lead to brown spots. 

To address your yard’s drainage issues, consider aerating your lawn. Improving compaction will allow water to hydrate your flora and enter the water cycle rather than pool above the soil.

Additionally, install gutter alternatives such as French drains or redirect downspouts to channel excess water away from your lawn. Addressing improper grading in your yard can also help water flow away from problem areas.

3. Improve soil health

Improving the health of your soil not only helps prevent brown spots but also contributes to a robust and dense lawn that fights back against weeds. Start by testing your soil to determine its pH and nutrient content. Amend the soil as needed based on the results.

4. Apply pesticide

Clearing your yard of pests without a pesticide can prove challenging. Choose one specially formulated to target the type of pest (or pests) you’re dealing with. Always follow the instructions carefully and avoid overuse. 

Once you’ve eliminated the infestation, look for signs of additional pests and take preventive measures to avoid future issues. For example, keep your yard free of debris, fallen leaves and standing water. Regular mowing can also help deter pests from calling your yard home.

For an organic approach, consider applying neem oil, which has insecticidal properties that repel many lawn pests, including grubs and Japanese beetles.

5. Trim and thatch

Overhanging trees or excessive thatch buildup can contribute to brown spots by limiting sunlight and air circulation to healthy grass. To tackle this issue, regularly trim tree branches to allow more sunlight to reach your lawn. 

Use a dethatching rake to remove excessive dead grass, roots and debris if you suspect your grass is struggling.

How do you prevent new brown spots from forming?

Once you’ve rid your lawn of brown spots, devise a plan to prevent them from returning. The following tips can help you maintain your grass’s lush green look.

Keep a healthy lawn

Maintaining a healthy lawn will help prevent brown spots. No matter your grass type, commit to a routine mowing, watering and a fertilizing schedule.

Cut grass between 2 and 3 1/2 inches with recently sharpened mower blades. Water deeply rather than frequently. Grass needs about 1 inch of water every week. Finally, avoid overfertilizing, as excess nitrogen can lead to brown spots.

Plan out the landscaping

Strategic landscaping can play a significant role in preventing brown spots caused by excessive shade or sun exposure. As you plan upgrades or renovations to your current landscaping, consider sun and shade patterns throughout the day. 

If areas of your lawn receive excessive sun, plant trees or install a shade structure to reduce the risk of brown spots from heat stress. Minimize foot traffic by creating paths with stepping stones or pavers to keep people off your grass.

Designate a doggy corner

To prevent brown spots caused by dog urine damage, pet owners should establish a designated area for their outdoor business. Train your dog to use a specific spot for bathroom breaks, preferably in an area where the grass is less visible or where urine can be diluted easily with water after each use. 

What’s next?

Now that you’ve taken proactive steps to address brown spots in your grass, you need to maintain its health and prevent future issues. Similar to restoring a lawn full of weeds, you’ll need to follow regular lawn maintenance practices, including mowing at the proper height, watering deeply but infrequently and fertilizing according to soil test results. 

Friedman suggested that if you can’t find an obvious answer to your brown spots or if they keep coming back, consult a lawn care company for a clear diagnosis. 

You can enjoy a full, green lawn free from brown spots year-round by staying proactive and attentive to your lawn’s needs.