There are many homemade remedies that can kill weeds, such as soap, salt, white vinegar or bleach. These solutions, however, are not selective and will also kill the grass in your lawn or plants in your garden. Corn gluten meal, on the other hand, works to kill weeds such as crabgrass, dandelions, curly dock, knotweed, lambs quarters, pigweed and plantain without damaging your lawn grass. Corn gluten meal is a byproduct of the corn syrup industry and differs from corn meal in that it has a higher protein content. The protein stops root growth in germinating seeds and eventually kills them. Purchase corn gluten meal at landscaping, gardening or hardware stores.
Spread corn gluten meal over the area during the early spring. Do not worry if the corn gluten meal touches the grass, it will not kill lawn grass. Spread between 10 and 20 pounds per 100 square yards of lawn.
Let the corn gluten meal sit on the area for six weeks. The solution will work to block new seeds from growing and needs several weeks to ensure that the weed's growing cycle has halted.
Apply the corn gluten meal again in the middle of the summer months.
Apply the corn gluten meal again at the end of the summer.