Types

• Vinegar is available in two acetic acid concentration levels: 5 percent and 20 percent. The lower concentration household vinegar is effective in killing young weeds. U.S. Department of Agriculture tests show that household vinegar has a strong enough concentration of acetic acid to kill weeds during their first two weeks of life. The tests show that the 20 percent concentration vinegar kills 85 to 100 percent of weeds during all growth stages.
  
  

How It Works

• Weeds absorb vinegar through the leaves and pull the chemical through the cellular system. The increase in acid damages the cells, causing the plant to wither and die. Grass and weeds have the same type of cellular system, so a spill on a grass area will produce the same results as spraying on weeds. A 5 percent concentration may not have enough acetic acid to travel to the root system of all weed types, especially mature weeds and those with fuzzy leaves. Household and high-concentration vinegar will kill grass in the same manner as weeds. High-concentration vinegar is an herbicide grade and only available at gardening stores or through chemical suppliers. Use caution with high-concentration vinegar to prevent burns to your skin or eyes.
  
  

Application

• The best method of using vinegar for weed control is spraying it on the weed leaves as a spot treatment. Avoid spraying vinegar across the lawn to prevent damage to the grass. Use a spray bottle or spray canister with flexible hose to help you keep the vinegar treatment isolated to weeds. Monitor the weeds several days after the application and repeat the spot treatment, if needed.
  
  

Considerations

• Wear hand and eye protection when using high-concentration vinegar on your lawn. Long sleeves and long pants will protect your skin from an accidental spill or spray toward your body. Store all chemicals in an area where children do not have access.
  
  Adding 1 oz. of dish soap to 1 gallon of household vinegar may increase the effectiveness of the lower-concentration vinegar. This mixture may not penetrate waxy and fuzzy leaves, but you can apply it to the soil around the stem for better results. Use caution when applying vinegar to the soil to prevent burning the grass around the weed.