How to Kill Dandelions With Vinegar
- 1). Heat vinegar before you apply it to dandelions. Vinegar is a mild acid that kills weeds, and boiling water also kills weeds, so boiling vinegar will work better than cool vinegar or hot water.
- 2). Add salt to the vinegar for a stronger weed-killing mixture. Combine 1 pound of salt and 1 gallon of white table vinegar (5-percent acetic acid). Stir to completely dissolve the salt. Add a surfactant, such as dish soap (1 tsp.) and use in a spray bottle to spray on dandelion leaves, or a syringe to inject into the crown of the plant. Repeat as necessary.
- 3). Increase the strength of the vinegar before applying it to dandelions by boiling off some of the water. White table vinegar has an acetic acid content of 5 percent, which boils at about 100.6 degrees Celsius (213 degrees Fahrenheit), but pure acetic acid boils at 118.1 C (244.5 F). Since water has a lower boiling point than acetic acid, if you boil table vinegar at temperatures below the acetic acid boiling point, it will evaporate some of the water, leaving a stronger concentration of acetic acid. Use caution when handling this stronger solution: do not breathe it in, and remember that the acid is now too strong to be edible.
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