Why Are There Brown Spots On My Lawn?

Updated: Sep. 01, 2023

You take great pride in how your lawn looks. So when you see those ugly brown spots tarnish your masterpiece, don't get angry. Get busy.

Each of those brown spots in your lawn tells a different story. Let’s look at a few reasons why they may be there.

What Does Brown Grass Look Like?

Brown grass can come in many different shades, shapes and sizes. But in general, it looks dead. Sometimes these brown spots mean the grass is actually dead. Oftentimes it’s just dormant, a temporary situation, and the grass will bounce back on its own or with a bit of TLC.

What Are Some Common Reasons Brown Spots Show Up in Grass?

Dog Spots

Dog urine has a lot of salt in it. That concentrated salt can kill grass.

Scratching up the spot and removing the dead material is a good start. Treat the spot with gypsum to neutralize the urine and then flush the area with lots of water. This will move the urine salts through the thatch and soil. Finish by reseeding the spot, covering lightly with soil and keeping the area moist during seedling establishment.

Soil Compaction

If you have a hard time sticking a screwdriver into a brown spot and water tends to pool on the surface, you probably have a soil compaction problem. These compacted areas can be caused by lots of foot or vehicle traffic, or heavy native soils.

You can rent a core aerator for a half-day that will help loosen the soil. And if you have time, go over your entire lawn. It will benefit greatly. If only a few areas are compacted, use a pitch fork and punch several holes into the compacted area. The easiest time to do this is when the ground is soft after a rain or irrigation.

Dry Soil

Like all plants, grass needs water to survive. Rainwater is the best. But when you can’t rely on Mother Nature, hand-watering, lawn sprinklers or in-ground irrigation are great options to prevent dry grass. When grass “burns out” from extended drought, the resulting brown spots may actually be patches of dead grass. Most lawns need about one inch of water per week to remain green and healthy.

Chemical, Fertilizer or Gasoline Spill

If brown spots quickly and mysteriously appear, look for possible soil contamination. Dead grass from fertilizer and chemical spills can be flushed with water, just like dog spots, but gasoline or other petroleum spills are trickier. These can’t be flushed through the soil, so you may have to dig out the contaminated soil and replace it before reseeding these spots.

Disease Activity

Some common lawn diseases, such as dollar spot, brown patch and necrotic ring spot, show up in your lawn as discolored or unhealthy-looking grass. Sometimes a quick change in the weather will make them go away. Other times, you may need to alter the way you fertilize, water or generally maintain your lawn.

Fungicide treatments, like BioAdvanced Fungus Control for Lawns and Syngenta Headway G, can also be used to curb these diseases. You may want to consult a lawn care professional for positive disease identification. And, of course, if you treat your own lawn, always read the safety precaution.

Insect Damage

Damage from insects, such as grubs and chinch bugs, can look a lot like drought damage. Look for telltale signs of insect activity. If you can easily pull up the grass from the surface (like a bad toupee), it means those grubs have chewed off the roots just below the surface. Grub control products containing chlorantraniliprole, such as Scotts GrubEX, are safe to use and pollinator friendly. These products prevent grubs from forming in the first place.

Insects that cause damage above ground, such as chinch bugs, can kill grass using piercing mouthparts that literally suck the moisture out of the grass blade. Talstar is a great product for controlling chinch bugs and other surface feeding insects.