Vinegar is a great herbicide for many plants. It can be sprayed directly onto the leaves and stems of most plants in your garden. It will kill weeds quickly, and it will keep them from coming back. Vinegar is also effective as a preventative measure to control the growth of weeds before they start to sprout. The best time to use vinegar is during the first few weeks of spring when the soil has warmed up and is moist. You can use vinegar on weeds, grass, annuals, perennials, shrubs, trees, vegetables, fruits, roses, and even houseplants. It’s important to be careful when using vinegar on your vegetables, however, because it can burn them if it is sprayed directly on their leaves. If you are spraying vinegar on a vegetable, wait until the sun is shining and the temperature is above 60 degrees Fahrenheit.