Natural Weed Killers for Vegetable Gardens

Acetic Acid

• Acetic acid is in vinegar. However, vinegar must contain at least 20 percent acetic acid to kill weeds. The type at grocery stores typically contains 5 percent. Gardeners can purchase acetic acid weed killers at a local gardening store. This organic weed killer is most effective when applied on dry days on smaller weeds.

Corn Gluten

• Corn gluten prevents grass weed seeds from germinating, according to the University of Minnesota. Apply corn gluten at the beginning of the growing season or in late April. Reapply it in mid-August. Use 20 lbs. of corn gluten per 1,000 square feet of soil. Water the corn gluten immediately after applying it on your vegetable garden. The corn gluten granules prevent weed seed germination for five to six weeks, according to the University of Minnesota.

Citric Acid

• Herbicides containing citric acid kill existing weeds. When looking for a citric acid-containing herbicide at a local gardening store, make sure it contains at least 20 percent citric acid. This herbicide burns the plant when applied. Use on wind free days so it doesn't contaminate neighboring plants. Placing plastic over rows of plants protects them from the spray.

Organic Mulch

• Organic mulch prevents weed seeds from germinating, smothers existing weeds, locks in soil moisture and insulated the vegetable garden. Choose from a variety of mulch types, such as wood chips, hay, pine needles, pine bark, compost and grass clippings. If you use grass clippings, make sure that you aren't using chemically treated grass. Spread a 3- to 3-inch layer of mulch from 2 inches away from the base of your vegetable plants and around the garden.