Vinegar for Killing Crabgrass

Vinegar

• Vinegar contains acetic acid. While it doesn't contain a high enough concentration of acid to burn your skin, it is strong enough to damage some organic material, including mold spores and plant tissues. This is what makes vinegar an effective natural cleaner. In high enough concentrations, it can kill plants. Whether using it as a cleaner or a killer, choose white vinegar. You don't need the additives in red or cider vinegar for these tasks.

Use

• Crabgrass grows around the world in many different climates. It is an opportunistic lawn pest, showing up in lawns that are poorly fertilized or do not receive enough water. It usually starts in a small patch and then spreads outward, taking up as much space in your yard as it can. To kill it using vinegar, spray the leaves until they are thoroughly coated. The acetic acid damages the blades of crabgrass, causing them to turn yellow and wither. Reapply the vinegar every three or four days until the crabgrass turns brown and dies.

Issues

• While vinegar kills blades of grass, it cannot soak into the soil deeply enough to kill grass roots. After the visible leaves die, the roots can start growing again, and soon you'll have a crabgrass problem in the same area. Vinegar doesn't just damage crabgrass; it will burn the leaves of any other plants it touches. While it won't kill crabgrass roots, if you get enough in the top layer of soil, it could be a challenge to grow anything in the cleared patch until the vinegar has washed out of the dirt.

Considerations

• If you need to kill a small patch of crabgrass, vinegar will do it as long as you dig up and remove the roots. For larger patches, a sheet of plastic is a more efficient crabgrass killer. Cover the crabgrass with a thick sheet of plastic, like that used for pond liners. Under the plastic, deprived of sunlight and water, the grass will die in a week in the summer or two weeks in winter. To speed the process, spray the crabgrass with vinegar before covering it with plastic.