Will White Vinegar Used As a Weed Killer Hurt My Lawn?

An All-Around Herbicide

• Acetic acid is effective against all green plants, be they weeds or your prized orchids. Vinegar must be applied directly to whatever you want to kill and not to anything else. It cannot be sprayed over an area under the assumption that it will kill only the weeds and leave the lawn and flowers unharmed.

Where to Use

• Householders will find white vinegar to be most effective as a weed killer when it is used to get rid of weeds that have grown up in cracks in the driveway, in pebble and brick pathways and in stone or brick patios. In these circumstances you can spray the area and not have to worry about accidentally killing the lawn or your other plantings.

In Driveways and Patios

• Acetic acid is available in concentrations from 5 percent to 100 percent. For the purposes of killing the normal weeds that turn up in the driveway or on the patio, a 5 percent concentration is fine. This is the concentration that you would find at the grocery store in the salad dressing aisle. Five-percent acetic acid will kill the top growth of weeds, but will not kill the roots. Apply a 5-percent solution of acetic acid by putting it in a spray bottle with a hand pump (such as the bottles window cleaner comes in) or, if you have a large area, with a yard and garden sprayer.

Eradicate Weeds

• Stronger concentrations of vinegar are needed to eradicate annual weeds such as foxtail, lambsquarters, pigweed, and velvetleaf. Solutions of 10 percent, 15 percent and

  20 percent acetic acid have been shown to provided 80 percent to 100 percent control of some annual weeds. When buying higher concentrations of acetic acid, look for products specifically labeled for home use. Purdue University lists Bradfield as a supplier. Acetic acid at these concentrations can cause skin irritation and permanent eye damage. Follow the manufacturer's directions very carefully.