Weeds pop up just about anywhere, creating a hostile environment where the desirable plants have to compete for nutrients and water. Small infestations can generally be controlled with manual removal while chemical herbicides are readily available to take care of weeds infesting a large area. However, chemical herbicides are not always the best course of action, especially when you have children and pets. Instead, consider using a natural weed killer mix for large areas overrun with undesirable plants.
1. Vinegar and Weeds
Vinegar with a 20-percent acetic acid can help control various weeds. However, homemade vinegar weed killer is nonselective and will damage or kill just about any vegetation it encounters. So you must take care when applying it near desirable plants. Sixty gallons of the homemade weed killer using a rate of 20 percent vinegar and 80 percent water will treat about an acre, according to the Center for Environmental Farming Systems website. This mixture provides about 80 percent control over broadleaf plants susceptible to vinegar.
2. Corn Gluten Meal as a Pre-Emergent Herbicide
For a natural pre-emergent herbicide, consider using corn gluten meal to prevent weeds from germinating. Twenty pounds of corn gluten meal spread evenly over 1,000 square feet and then dampened with water will help prevent weeds from sprouting. Apply corn gluten meal in late April to early May, and again in mid-August. Corn gluten meal has no effect on weeds already sprouted. If applied correctly, it can provide up to 6 weeks of weed suppression, according to the University of Minnesota Extension website. You must, however, apply pure corn gluten meal and not the distiller grain or corn gluten used in animal feed.
3. Homemade Herbicide Found in the Laundry Aisle
Borax is a versatile product used as a laundry booster, deodorizer and all-purpose cleaner. It can also help control the aggressive and invasive weed creeping Charlie (Glechoma hederacea), which is hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9. To treat a 1,000 square foot area, dissolve 10 ounces of borax in 4 ounces of warm water, and then mix this solution in 2 1/2 gallons of water. Use a pump sprayer to evenly broadcast the solution over the area. Only apply the borax weed killer once per year and never more than in two consecutive years.
4. Warnings and Considerations
Even though natural weed killers are generally considered less harmful than chemical herbicides, they can still pose a risk if not used properly. For example, vinegar with a 20-percent acetic acid can cause skin irritation while borax can cause gastrointestinal distress if ingested. Always err on the side of caution. Pregnant and nursing women should not apply any herbicides, homemade or otherwise. And do not allow children or pets access to these herbicides.
- Center for Environmental Farming Systems: Weed Management on Organic Farms
- University of Minnesota Extension: Corn Gluten Meal A Natural Pre-Emergence Herbicide
- Carolina Biological Supply Company: MSDS - Vinegar
- University of Minnesota Extension: Using Borax to Control Creeping Charlie
- Monrovia: Variegated Ground Ivy
- OMSI: Borax Material Safety Data Sheet
- David De Lossy/Photodisc/Getty Images