6 Reasons Your Lawn Is Turning Brown–and How to Fix It

When your lush emerald lawn starts going off-color, you might wonder where you went wrong. After all, you’ve fertilized, aerated, watered, and done all the right lawn care things. So why is your turf looking less than terrific?

There’s no single reason why green grass goes brown. "It could be a normal response to temperature or an attack from disease or pests," says Justin Hancock, a horticulturist at Costa Farms. It’s also common to see browning, particularly in spots, if there’s a chemical spill, over-application of fertilizer, or a concentration of pet urine, and other reasons, he says. Ahead, we spoke to lawn experts about the common causes of a browning lawn and how to correct them.

Seasonal Causes

Certain culprits are indeed more prevalent at certain times of the year, according to Phil Catron, president and founder of NaturaLawn of America. Here’s what’s likely browning your grass during each season:

• Spring: A hard freeze can damage actively growing grass, or you may see early signs of lawn disease
• Summer: Rain-free periods can cause drought, lawn insects are more active, and cool-season grasses may go dormant to protect themselves
• Fall: Early frost can hit before the lawn fully hardens off, and damage from disease or lawn insects can become more noticeable
• Winter: Warm-season grasses will go dormant when temps drop to protect itself

Grass health can also depend on the time of year combined with the type of grass. Cool-season grasses tend to grow best when the temperature is below 75 degrees Fahrenheit and will grow more slowly and get stressed in the heat of summer, Hancock says. Warm-season grasses, on the other hand, do better when temperatures are above 80 degrees and tend to go dormant in cooler months. 

It’s also common for lawns to turn brown seasonally. "This is a normal part of the grass’ lifecycle and will not harm your grass long-term,” says Marc Mayer, director of technical operations at TruGreen. 

If the top of your grass is dry and brittle, but there’s green at its base, then it’s likely dormant. To confirm, use the "tug test": Grab a handful of grass and yank. If it pulls up easily, it’s probably dead. If it resists, it’s more likely to be dormant.

It’s Too Dry

Drought conditions take a toll on grass. You might see browning, stunted growth, increased susceptibility to diseases and pests, and ultimately, dieback of grass and other plants, according to Jason McCausland, a technical coordinator at Weed Man. Prolonged drought can lead to soil compaction and decreased soil fertility, making it harder for the lawn to recover.

How to Fix: Watering can help rehydrate dried, dormant grass, especially warm-season varieties (e.g., Bermudagrass, zoysiagrass, St. Augustine grass, and centipede grass). Generally, lawns like about 1 to 2 inches of water per week. For best results, McCausland recommends mowing high at the first signs of stress, watering your lawn early in the morning two to three times a week, and removing a thatch layer if you have one. 

However, if you have cool-season grasses (e.g., Kentucky bluegrass, perennial ryegrass, tall fescue, and fine fescue), you can expect them to go dormant in high heat, and more water won’t help. Instead, Catron suggests reducing watering to every seven to 10 days. "This will keep the plant alive so that when weather conditions improve, the lawn will recover much more quickly," he says. 

Fungal Disease

Diseases can attack grassroots or leaf tissue and can vary by season and region. According to Catron, warm, humid weather can make your lawn vulnerable to these root-targeting diseases:

• Brown Patch: An irregularly shaped patch of brown or tan grass, often developing after grass has been water-soaked 
• Summer Patch: Circular patches of dead or thinning grass that can look yellow before turning brown
• Pythium Blight: Water-soaked patches of grass that turn brown and die. In the early morning, it can appear to be coated in a white, fuzzy, mold-like substance
• Necrotic Ring Spot: Circular patches of yellow or brown grass with a ring of healthy grass around the outer edge

How to Fix: Treatment may not be one-size-fits-all, but good strategies, according to Catron, are to improve air circulation and soil drainage, avoid over-fertilizing, and consider using fungicides. A local gardening expert can confirm the type of fungus and recommend the best fungicide to use. "Keep an eye on lawn conditions and be proactive about addressing any signs of disease to minimize damage and improve recovery chances,” Catron says. 

Pests

Pests commonly responsible for brown spots include grubs, chinch bugs, armyworms, and sod webworms. "These insects feed on grass roots, stems, or blades, leading to visible signs of damage such as brown patches, thinning turf, or irregular growth patterns," McCausland says. The extent of the damage will depend on environmental conditions, turfgrass species, and the type of pest attacking your grass.

How to Fix: Dig a few holes in your lawn and look for the little critters. Grubs, for example, are white or cream-colored beetle larvae that often curl into a tight C-shape when disturbed. If you see them, apply a pesticide or add beneficial nematodes. "It may take a couple of weeks for the grubs to begin dying, then another two to three weeks for grass roots to regenerate and start producing new growth if there’s light damage," Hancock says. "If there’s heavy damage and the majority of the grass is dead, you may need to reseed/sod."

Compacted Soil

If your soil is compacted, the regular channels for air and water get compressed, leaving the grassroots starved for air, water, and nutrients. "One common sign your lawn is compacted is that it’s extra hard compared to the surrounding soil, and water doesn’t drain readily after you irrigate or after a rain," says Hancock.

How to Fix: Aerate the soil. If it’s a large area, rent an aerator or hire a company to do it for you. If it’s a small area, try piercing it with a garden fork a bunch of times to create holes that allow moisture and nutrients to filter through. (Sadly, Hancock notes, aeration sandals don’t work.) Expect your grass to recover in about four to six weeks.

User Error

At the end of the day, it could be something you’re doing or not doing that’s causing your lawn to brown. One common mistake is inadequate or, worse, over-fertilization. "Too many nutrients applied at once or over time cause a buildup of nutrient salts in the soil that can harm plant roots," Hancock says. "Without healthy roots to absorb moisture and nutrients, the grass blades are sure to go brown."

There’s also improper irrigation, excessive thatch, and bad mowing practices. "If a lawn is mowed too short during the hot summer months, it can cause irreparable damage," McCausland says.

How to fix: Aim to mow and water and apply fertilizer as needed, but keep in mind that no grass is immune to common lawn problems. The key is to catch them early. "Paying attention to your lawn and identifying issues as they first start goes a long way to preventing browning," Hancock says. "It’s easy to overlook when you see your lawn every day, but just about every issue is easier to deal with—and with less recovery time, when caught early."