Are you looking for a garden-safe weed killer that won't harm your vegetables, flowers, wildlife or pets? There are a variety of options---chemical, organic, homemade and commercial products---for this type of weed killer (or herbicide).
Vinegar or Acetic Acid
Vinegar, or acetic acid, is an effective weed killer that has been used for centuries. For heavy-duty weed killing, use the highest percentage of vinegar you can find. Common table vinegar is usually 5 percent acidity. You may find up to 18 percent acidity in vinegars.
Many vinegar weed-killer recipes call for adding salt. However, salt stays in the ground a long time and will prevent plants or grass from growing in that spot. Do not use salt applications near any of your favorite plants, or anywhere you intend to grow anything for the next few years. Another addition to many vinegar weed-killer recipes is dish-washing liquid. If you use such a solution, be aware that some detergents have phosphates harmful to the environment.
Fill a spray bottle with vinegar and spot-spray (do a foliar spray, which means apply it on the leaves or blades only) any weeds you encounter. Do not pour the vinegar onto the ground as it may spread to the roots of good plants and it may reduce the fertility of the soil and kill beneficial organisms.
Do not let the vinegar get onto any vegetable or flower plants, as vinegar is a broad spectrum plant killer---it does not discriminate between "good" plants and "bad" plants.
Even though vinegar is an organic weed killer, it may still damage the environment if improperly used.
Steep bulbs of garlic in hot water for this spray. Pour the liquid into a spray bottle and use it as a foliar spray. You may spray it on the roots of weeds. Keep the spray off any "good" plants you intend to keep. Garlic spray has mixed reviews as a weed killer. It works best as an insecticide when sprayed directly on the offending insect. When using as an insecticide, be careful not to damage the plant with a spray that is too strong.
Corn Gluten Meal (CGM)
An organic method for weed control, corn gluten meal (CGM) may be purchased in commercial products online or at lawn care centers. CGM is an effective weed killer or herbicide, which is safe for pets and the environment. Use according to package instructions. When applied in early spring, CGM prevents germination of weeds.
Pure lemon juice can be used as a garden-safe weed killer. It is not harmful to pets or the environment. Spray it directly onto the offending weeds, careful not to let the spray come into contact with good plants.
Glysophate is a commercial herbicide and was formerly marketed under the brand name Roundup(R). It is a broad spectrum herbicide and is commonly sold in lawn centers everywhere. There is much debate on whether this weed killer is actually safe for the environment, pets, wildlife or humans. It is mentioned here because it is a prominent commercial product which is advertised for the purpose of being a garden-safe weed killer.
Herbicidal soaps may be homemade or purchased in a commercial brand. Dish-washing liquid is often used for this purpose. As mentioned above, be aware that many detergents have phosphates, which have been shown to be harmful for the environment. Check the label to see what ingredients are in the soap prior to use.
Home recipes for herbicidal soap often blend dish-washing liquid, vinegar and salt. As mentioned previously, be careful in using salt as an herbicide since it de-fertilizes the soil and will prevent anything from growing for a long time.
Landscape fabric is one of the safest, easiest weed killer and weed-control methods. Simply lay the fabric onto the ground in areas where you wish to kill weeds and prevent their seeds from germinating. Landscape fabric is safe for pets, wildlife, humans and the environment. Once in place, it will last a long time. It is an excellent addition to the garden.