Mulch is often applied around trees and in a garden to help retain water in the soil and eliminate weeds. Mulch can also help insulate the ground and protect the roots of your plants from freezing in colder climates. All mulch will eventually break down, at which point unwanted weeds may appear in the mulched area. When weeds occur, several options are available to help remove and eliminate the weeds from the mulch.
Things You'll Need
Liquid dish soap
Pull the weeds out by hand. When pulling, pull from the bottom of the weed to be sure that the root is extracted. By using this method you will not risk the health of your plants and trees by spraying potentially deadly weed killers.
Apply a new layer of mulch, alternatively, that is approximately 2- to 3-inches thick on the mulched area. The new mulch will cover and smother the weeds, eventually killing them. The weeds will then break down naturally, along with the mulch.
Pour boiling water on the weeds, but be careful not to burn yourself.
Spray the weeds using a spray bottle with 5 tbsp. of liquid dish soap mixed with 4 cups of water. Alternatively, you can use 3 tbsp of rubbing alcohol in place of the liquid dish soap or fill the bottle with undiluted vinegar. Be careful not to get any of these mixtures on the plants you would like to remain in your garden.
Apply a weed controller, such as Roundup, Ortho Weed-B-Gone or Scott's Weed and Grass Killer. Be sure to follow the instructions on the bottle and make sure there are no plants that you would like to keep in the applied area.