How to Keep Grass from Growing Up Underneath My Deck

A deck attached to your house is the perfect place to grill, relax and enjoy time with friends or family. Unfortunately, your deck can become a source of frustration if grass starts growing up to the deck from underneath it. With a bit of planning, though, you can stop unwanted grass from growing under your deck and possibly improve the overall look of your yard in the process.

Young woman crouching on decking, examining potted plant, side view
credit: Tay Jnr/Digital Vision/Getty Images
Decks can feature ornamental and potted plants.

Weeding and Maintaining

Perhaps the most obvious solution to grass growing underneath a deck is to focus more effort on weeding and lawn maintenance around and below the deck. It may require additional time spent with a grass trimmer or manual weeding to keep grass in the deck area as neat as possible. Those methods are more effective for a raised deck than a low deck, which may not allow enough room for you to trim or pull the grass beneath it easily.

Using Herbicide Solutions

Another potential solution to unwanted grass growing beneath your deck is to use an herbicide to kill it. This approach can be particularly effective if grass grows under your deck in areas where other methods cannot be used. Chemical herbicides are readily available, but you can make your own herbicide using vinegar or a solution of 1 ounce of vodka mixed with 2 cups of water. Add a few drops of liquid soap to the vinegar or to the vodka-water solution when putting it in a sprayer to help it cling to the grass. These homemade herbicides can be used throughout the year, though, like other herbicides, they should not be used on a windy day or when rain is expected later the same day.

Mulching and Landscaping

Undertaking a landscaping project may seem like a lot of work to prevent grass from growing under your deck, but it is a permanent solution that can improve your deck area's appearance. The existing grass should be killed and removed to ensure the best possible results. Then a layer of landscaping fabric should be placed where the grass was located and a 1- to 2-inch-thick layer of mulch or gravel placed on top of the landscaping fabric. Around the border of your landscaping, place edging or a similar boundary that complements your deck.


An alternative to mulching or installing rock landscaping, xeriscaping is the replacement of fast-growing grasses and other turf with plants that grow slowly and require little water. Such plants include woolly yarrow (Achillea tomentosa), which is hardy in U.S. Department of Agriculture plant hardiness zones 2 through 9, and buffalo grass (Buchloe dactyloides), hardy in USDA zones 3 through 9. If desired, use edging or other decoration to separate the xeriscaping from the rest of your yard. The xeric plants will keep the turf under control around your deck while adding flair to that area.