You should add 1 to 4 inches of mulch, depending on your garden type and needs. Keep in mind that no amount of mulch can completely prevent weeds, but a heavier coverage (closer to 4 inches) can suppress weeds enough that you are only seeing them sprout every few weeks. Finer mulch prevents weeds more effectively than large mulch, so if you’re using mulched leaves or shredded bark, 1 to 2 inches will likely suffice, while 3 to 4 inches is best for larger mulch, like bark chips or straw.

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.

Lawns with steep slopes can benefit from having quack grass. Quack grass's long roots and runners can help to prevent soil erosion on hillsides. Additionally, bird lovers may enjoy the fact that quack grass seeds are an attractive food choice for their avian friends.

Weeds may grow back when pulled out if the root is not completely removed. Invasive weeds can regrow from just a small portion of remaining root, so using a weed-pulling tool can help ensure you remove the entire root. Weeds may grow back faster if roots aren’t fully removed, and incomplete removal could cause them to spread as well.