Grasses and other opportunistic weeds will grow wherever there is hospitable soil, including cracks in concrete. This can lead to unsightly grass growth on your walkway, driveway or patio. The easiest way to stop grass from growing in your concrete is to kill existing growth and fill any cracks to prevent future germination of the grass seeds.
Things You'll Need
2 cups water
1 cup salt
Fill a soup pot with 2 cups of water and 1 cup of salt. Bring to a boil.
Bring the boiling salt water outside and pour it directly on the grass in the concrete. The salt and hot water will kill the grass.
Fill the cracks with baking soda to kill any ungerminated seeds. Leave the baking soda for two days.
Sweep out the baking soda and any other materials from the crack with a broom. Spray the crack with water from a garden hose to thoroughly clean it. Let the concrete dry overnight.
Fill the crack with concrete crack filler until the filler comes up over the edges of the crack. Use a putty knife to smooth the filler so it is level with the concrete. Let the filler dry according to the package directions.