Adding vinegar to your lawn increases the acidity of the area, which can kill quack grass present above the ground. However, putting vinegar in your yard will also kill the grass. Unfortunately, the below-ground quack grass rhizomes remain very much alive in the presence of vinegar and will soon sprout again.

If you spray a DIY vinegar solution that contains high salt, it can disrupt the soil's structure and make it difficult for plants to grow. That's why it's vital to avoid spraying vinegar solution on areas where you are trying to grow plants and flowers. When using a mix of vinegar and soap, some say you can plant a few days after the vinegar dries. 

Vinegar cannot tell the difference between weeds and desired grass types; it kills everything it touches. Only use a vinegar or vinegar-based solution if you are relatively confident that you can navigate around the plants and grasses you want to keep. Also, don’t spray vinegar on a windy day, or it will blow onto other plants.

Very carefully. You should be cautious when using any of the above methods, as any one of them could lead to you accidentally killing desired grasses and plants. However, there are selective herbicides that can target certain plants over others. Look for a product that only affects the type of weeds you want to eliminate and spares the plants you want to keep.