My Grass Has Brown Spots

Dog Urine

• Dog urine contains concentrated amounts of nitrogen, which burns the grass when deposited in the yard. Yards will continually get brown spots when dogs are allowed to run rampant throughout. A quick fix is to leach the soil as soon as you see your dog urinate on the yard. Leaching the soil helps remove the excess nitrogen. Keeping your dog in one place, such as in a dog run, will protect the rest of the grass.

Fertilizer

• Much like dog urine, too much nitrogen spread across the lawn can cause dead spots. Furthermore, rotary fertilizer spreaders that contribute an uneven spread may cause burnt areas. Typically, gardeners should avoid spreading more than 1 lb. nitrogen per 1,000 square feet. Using a quick release fertilizer may be tricky, because it can burn up grass. Refrain from fertilizing water stressed grass or on extremely hot days. Water the lawn after fertilizing to allow the nutrients to absorb into the soil.

Lawn Mowers

• Lawn mowers with dull blades may cause grass browning. When dull blades shred grass tips, the grass dries out too rapidly, according to Colorado State University Extension. Lawn mower blades must be serviced or sharpened at the beginning of the growing season. Also, keep your grass at a height that doesn't cause stress to the root system. Grass that is mowed too low will brown, decline in health or die. Likewise, mowing too low puts your grass at risk for contracting a fungal disease.

Thatch

• Thatch is the layer of dead and living organic matter between the grass and the soil. A thick layer of thatch that is over 1/2 inch can contribute to brown spots. Thick thatch reduces air circulation, prevent nutrients from being absorbed into the soil and provides a hospitable environment for fungal diseases. Rent a dethatcher and remove you thatch after your grass has had time to green up. Typically, cool season grass should be dethatched in the spring and warm season thatch can be removed in the fall.