5 Causes Of Brown Spots In The Lawn

Posted on: 29 June 2023

Brown spots can ruin your beautiful lawn. Fortunately, there are only a few common causes of browning, so finding the culprit and fixing it is possible. 

1. Dog Spots

Dog urine is a common cause of brown spots, particularly in the lawn where it borders sidewalks or in your own pup's favorite places to urinate. Ammonia, urea, and nitrogen in the urine burn the grass, often causing it to brown out in the center and become greener around the edges. Repair requires excluding dogs from the lawn in the affected areas, then flushing the soil well with water before overseeding with new grass.

2. Fertilizer Burn

Nitrogen in fertilizers has the same result as dog urine — brown spots that may be bright green around the margins. The best way to avoid problems is to have your lawn service perform a soil test before fertilizing to ensure the right amount and formula of fertilizer is used. If you fertilize yourself, use a spreader or sprayer system so fertilizer is applied evenly and not in clumps. 

3. Water Issues

Too little water will definitely cause areas to brown out. Begin by checking your sprinkler heads near the brown spot to ensure they are all working properly. Compacted soil can inhibit water from soaking in, even if the sprinklers are working. In this case, you can solve the issue by scheduling a lawn aeration treatment to break up the soil. Your lawn service may also recommend raking up the thatch layer on top of the soil so water can better absorb into the ground.

4. Pest Damage

Certain pests will feast on grass and cause it to brown out. One of the most common of these pests are grubs, the larva of June beetles, which eat grass roots. All that remains is a loose mat of dead grass. Grub treatments must be applied when the grubs are most active, which will depend on your local climate. Your lawn maintenance service will know the best treatment windows for your area.

5. Low Mowing

Setting the lawn mower blade height to low will cut the grass blades too short, causing them to brown out and die. How high to cut the grass depends on the exact variety, but generally, it should be at least a few inches tall. Cool-season grasses, for example, do best at a range between 1 and 4 inches, while warmer-season grasses may only need to be 3 inches high after mowing.

Contact a lawn care service for more help if your grass is turning brown.