There is a safer alternative to using chemical weed killers in the garden. Vinegar can be used where children or pets play and will have less environmental impact than chemical-laden counterparts; its acetic acid component is a powerful weed killer. Ordinary table salt in small amounts can also quickly kill weeds. A mixture that uses liquid soap, vinegar and salt, will adhere to weeds better and help get rid of them.
A vinegar, soap and salt mixture will kill weeds fast, the Garden Counselor website reports — spraying will often result in a withered plant in a few hours, or kill tougher plants by the following day. Sometimes plants will require a second application.
Use in Limited Areas
Limit spray to just the weed, not surrounding plants. If you spray weeds in your vegetable garden, this solution can kill the good plants as well. The same kinds of concerns apply to many commercial weed killers.
Notes on Vinegar
White vinegar available in the grocery stores usually contains five percent acidity. This level of acidity is fine for this weed-killing mixture. Vinegar, when used as a weed killer, is considered “non-selective,” which means it may kill any plant it touches. It’s wise to test in a small area of the garden first — and continue accordingly.
Notes on Salt
Where vinegar shrivels the above-ground portion of weeds, salt gets to the roots, acting as a desiccant to draw water from the plant and, eventually, kill the root system. Limit the amount of salt in a weed-killing solution to avoid affecting roots of other plants. The risk of adding too much salt is that it can remain in the soil, making it more difficult to grow desirable plants in that location. This is why the recipe presented in Step 6 limits the amount of salt. Some choose to leave salt out altogether, Garden Counselor notes.
Adding Liquid Soap
According to the Healthy Child Healthy World website, diluted soap (such as dishwashing liquid) can kill weeds when used alone. However, adding vinegar greatly aids in the mixture's weed-killing action. Soap makes the solution easier to apply to plants, and helps keep it from migrating to other plants.
Use one gallon of white vinegar, add half a cup of liquid soap and two tablespoons of salt. Shake the mixture. Put the mixture into a spray bottle and spray on the leaves and stems of weeds only, avoiding surrounding plants. According to the Frugal Gardening website, this versatile mixture will kill grass between bricks, as well as weeds in the cracks along the driveway and between sidewalk section.
Using a natural weed killer is safer than commercial weed killers, less expensive and leaves fewer toxins in soil.