When you want to keep potentially dangerous chemicals out of the yard your kids play in, but you still want to get rid of weeds, using vinegar and lime juice might be the solution you're looking for. These organic options kill the weeds quickly without leaving a scary residue.
Why They Work
Vinegar and lime juice share an important weed-killing element: acid. This acid burns the cells of weed leaves, making the shrivel and turn brown, often within hours. Household vinegar typically is a 5 percent solution of acetic acid, but pickling vinegar is stronger. You can also find 20 percent vinegar solutions at garden supply stores, but you should understand these are much more dangerous than household vinegar. Lime juice is full of citric acid and while not quite as powerful as a 20 percent vinegar solution, it's not a danger, either.
How to Mix
Vinegar and lime juice work well on their own without needing to be mixed. For a more acidic solution, mix 4 ounces of lime juice with 1 quart of vinegar. Don't add water, which only dilutes the potency. According to University of Tennessee Extension, using these liquids is 80 to 100 percent effective in killing weeds when applied correctly.
How to Apply
Pick a hot, sunny day for your vinegar and lime juice application. The heat and sun help the acid burn through the plant faster. For best results, choose a day when no rain is expected so the solution won't be diluted. Pour the solution into a spray bottle and spritz the weed leaves, or pour the mixture directly over the weed. With most weeds, you'll see results within a day. Because the mixture doesn't leave residual chemicals in the soil, you can reapply the next day if necessary.
Although you're keeping your yard chemical-free, vinegar and lime won't stop new weeds from growing like some commercial herbicides can. You must reapply whenever new weeds start to grow; getting them in their first two weeks makes them easier to kill. Wear the proper safety gear when applying a vinegar and lime juice solution, especially rubber gloves and eye protection -- the mixture can burn your eyes if you splash it or rub your eyes after your hands touch the solution. Watch where you apply the acids -- they are non-selective, which means they will kill any plant they touch, not just the weeds. Spray or pour carefully so the mixture hits only the weeds. If you use a vinegar solution frequently, it can alter the pH of the soil, possibly making it difficult to grow plants.