Goodbye Weeds with 3 Simple Ingredients 1 Mix the ingredients Combine vinegar, salt, and a bit of mild soap. Sounds like a kitchen recipe, but dont drink it! 2 Apply under the sun Spray directly on the leaves on a hot, sunny day. I tried on a cloudy one absolutely no results! 3 Protect what matters Avoid spraying near your favorite plants, or they might get damaged too. 4 Repeat only when necessary Two or three times a year is enough to keep weeds away without harming the soil.