What Causes Brown or Dead Patches in Your Lawn?

Brown or dead patches on a lawn appear from time to time, even in the best-tended lawn. While reasons for brown patches can be from something as common as underwatering, overwatering, or animal urine, other underlying causes could also be at play. Pests, diseases, or burnt patches from salt or fertilizers could also be the culprits of dead spots.

If you're plagued by a not-so-green lawn, determine the cause and use whatever measures to remove the cause of the problem. Then, repair the bare patch by reseeding or a with a sod patch, and take precautionary measures with your lawn care moving forward.

Keep reading for some of the most common reasons why dead spots might occur on your lawn, and what to do about them.

Underwatering

If your lawn is underwatered, then it is exposed to periods of drought and dryness. Aside from the typical brown and bald patches, an underwatered lawn may also feel brittle and dry to the touch, and the grass will not spring back up after you step on it. You can also tell if your lawn is not getting enough water by measuring its growth as well as feeling the texture of the soil.

Before you leave the sprinklers on for hours, consider aerating your lawn and adding some fertilizer to help water retention. Then, begin watering with the correct amount of water for the space in need.

Overwatering

If your lawn has been overwatered, then you have provided it with too much water than it can retain. Signs of an overwatered lawn include mud and dirt, mushy soil, discolored patches of grass, an abundance of weeds or fungi, and thinning grass.

To fix this problem, stop watering your lawn completely and then slowly integrate water back into the grass once the area has dried out. Reducing the amount of water will help your lawn get back to its healthy state, but the damage caused by bacterial growth, pests, and bald patches may need a professional opinion.

Incorrect Sprinkler Coverage

Sprinklers that do not overlap or that miss an area completely may cause small areas of turf to brown out and go dormant. On the other hand, areas with too much coverage can cause the lawn to be overwatered. When watering, observe the sprinkler patterns for a while and make sure that your lawn coverage is uniform.

Thatch Buildup

If you notice clumps of lawn and dirt, it could be more than just dead grass. It could be thatch, which is a mix of dead and living plant material such as roots, leaves, and organic material. Thatch buildup develops naturally over time around the base of grass plants (above the soil and below the root of the grass). To determine if you have thatch, cut several plugs of lawn and examine them. Thatch will appear stringy and brown below green blades of grass. To remedy the problem, you will need to dethatch your lawn, which is as simple as breaking down the grass with a thatch rake.

Improper Soil Nutrients

Soil isn't just important for plants, your lawn needs it, too. The quality and pH of soil as well as the texture affect the health of your lawn when it comes to water and how much the lawn can hold. Healthy soil will contain nutrients as well as beneficial fungi and bacteria for lawn growth.

The ideal soil pH for lawns is between 6.0 to 7.0. You can test the pH of your soil at home by using pH strips. Obtain a sample of soil about four to five inches below the surface and place it in a glass. Add distilled water and gently mix to combine. Drain any remaining liquid and then insert a pH testing strip. Once you have addressed the imbalance of nutrients in your soil, you can balance out the soil pH or feed the grass an organic fertilizer mix.

Urine From Pets or Wild Animals

Dogs, cats, and wild animals urinating on your lawn will usually leave a telltale brown, straw-like patch due to the high concentration of urea that burns the grass. But just around this dead spot, there may be a ring of very dark green, unusually healthy grass—the result of a higher-than-normal nitrogen level. If you catch an animal urinating, then you may be able to prevent the burn by watering the spot thoroughly immediately afterward.

Heavy Foot Traffic

If you have pets, or kids, or just enjoy spending a lot of time outside, you may notice some parts of your lawn look a little worse for the wear. High-traffic areas of your lawn will commonly turn brown and die off, but they can be easily repaired by overseeding. Once you have applied the seed to encourage new growth, rope off these parts of the lawn so no one walks on it. You may also want to consider specific types of grass that can stand up to highly trafficked areas such as Kentucky bluegrass, Bermudagrass, and zoysia.

Grubs or Other Pests Below the Turf

Grubs are the larvae of various hard-shelled beetles, such as the Japanese beetle or June bug. A lawn can tolerate some degree of grub infestation, but if the concentration is high, dead patches will appear in your lawn. A strong sign that you are dealing with grubs is if the dead patch lifts away from the ground easily when you tug on the grass. Grubs eat the roots of grass and leave nothing to hold the grass in place. Addressing this problem involves reseeding or resodding preferably after you have dealt with the grub infestation.

Fungal Diseases

Lawn diseases such as snow mold can kill patches of lawn. If you see fine white webbing covering the lawn and gradually killing the grass, then that is a potential sign of a fungal disease. Fungal diseases are common and usually due to temporary environmental conditions. Good lawn care practices reduce the likelihood of recurrence, and there is usually no need for aggressive measures.

Spilled Chemicals or Gasoline

Spilled pesticides or broad-spectrum herbicides such as glyphosate (Roundup) will often cause dead spots in the lawn. Even if you have an appropriate weed killer, its concentration may be just a little too high for your lawn and can kill turf grasses. Chemical spills will often create an irregularly shaped dead patch that matches the shape of the spill. Water the spot thoroughly if you accidentally spill. Take extra care when you have strong chemicals near your grass, and be very careful about preventing a spill. It's better to prevent a problem than to try to fix it.

Salt Burn

In northern climates where salt is applied as an anti-icing measure, it is common to see dead spots appear along streets and sidewalks as grasses begin growing in the spring. Sometimes these areas will heal themselves with plenty of water in the spring, but you may be left having to reseed or put down more sod. Minimizing your application of salt on the sidewalks will help reduce future problems, but along roadways, your only option might be to look for non-grass groundcovers to plant.

Fertilizer Burn

Applying too much fertilizer or spilling fertilizer on your lawn may burn the grass leaves and leave you with a dead patch. If you catch yourself spilling fertilizer, water it thoroughly as quickly as you can to wash out the excess nitrogen. Load fertilizer spreaders while you are off the lawn. When you apply fertilizer, use the steady movement of a spreader to feed your lawn.