What Kills Grass Fast?

Weed Killer

• Weed killer products kill both grass and weeds, so avoid using these on your lawn. Instead, wear garden gloves and pluck weeds yourself. Pull the weed up gently from the root and leave the surrounding grass intact. This extra step can keep your lawn clean and free of weeds, without adding excess chemicals.

Animal Urine

• Animal urine from cats and dogs can kill grass quickly. Dogs often urinate in specific spots throughout the lawn and this causes grass to die, resulting in yellow patches throughout your yard. Place a small white picket fence around your yard to help keep stray dogs from urinating on your lawn. If you own a dog, train him to urinate in one spot in your backyard.

Vinegar

• Vinegar can also kill grass quickly. Try it on unwanted grass in the wrong spots such as sidewalks or the driveway. Pour distilled white vinegar into a spray bottle and spray it full strength on the unwanted grass to kill it.

Pests

• Pests can also kill grass quickly, but pest killers and insecticides can also do damage all by themselves. However, many types of pests naturally stay away from healthy plants. Keep your grass healthy by using a good phosphorus-rich fertilizer on an established lawn. The Healthy Landscapes website says not to use a phosphorus fertilizer on bare ground or low-density lawns, but it's recommended for mature thick grass. Keeping your lawn mowed to a height of 2 to 3 inches also encourages deeper roots and healthy grass.