Avoid using vinegar on or near your lawn, since it will kill the grass. Vinegar will raise the acidity of your soil. Before planting, test the pH of your soil and adjust it accordingly, if needed. Use horticultural vinegar with 20% acetic acid for increased effectiveness between pavers or on patios. The extra acidity will affect the pH balance of your soil and other plants.
You can use dish soap or dishwasher detergent in liquid or powder form. Dish soap can be used in conjunction with a lemon-vinegar mixture, but a soap and vinegar solution will be very effective.
You can use alcohol, vinegar, and lemon juice together in one mixture, but a solution that strong may cause soil damage.
Full strength solutions may penetrate the soil and kill the roots of plants other than weeds. They can also disturb crucial microorganisms in the soil. [4] X Research source
Set the nozzle to “stream” rather than “spray” if the weeds are growing close to plants that you don’t want to kill. Don’t forget – weed killer does not discriminate. It will kill any plant it comes in contact with, so use it carefully!
Dissolve 1/2 c (120 mL) salt into enough warm or hot water to fill your spray bottle. Apply the salt dry. Simply sprinkle the salt on the weeds you want to kill. This works particularly well on garden paths and along lawn edgings. [6] X Research source
You might have to repeat this several times over multiple days to sufficiently kill all the weeds. Add 1 tbsp (15 g) of table salt to the boiling water to make an even stronger solution.
Wear gloves and glasses while you handle the solution, since it may cause skin irritation. Never use this solution to control weeds in a vegetable or flower garden; it will damage veggies and flowers.
