I recently read a really good article about this... To kill weeds with vinegar, the vinegar would actually need to be extremely potently acidic vinegar... to the point of being dangerous. Pouring normal vinegar on the weeds will burn their leaves and they will turn brown and look dead, but it doesn't kill their roots, so you're really wasting your time. Round-up will be absorbed into the leaves and kill the roots.
Mary, our recipe is: 1 gallon white vinegar, 2 cups Epsom salts, 1/3 blue dawn dish soap. Spray on weeds on sunny day early in a.m. after dew is evaporated. This will kill any living plant so we only use it like in the driveway, in the gravel, or sidewalk cracks etc. not on the lawn.
Hi Mary - The struggle is real, isn't it?!? This is the most effective all-natural weed killer DIY that we use. It's even been featured on Hometalk! Hope this helps! Hugs, Holly
PS - We have a FREE eBook with recipes for all of my homemade and all-natural cleaners. You can download it here --> https://pinkfortitude.com/thank#GreenClean