Our favorite method of eradicating weeds is pulling them up by hand. Although hard on your knees and back, this method must have therapeutic results. Why else would it hurt so much?
Chemical companies developed herbicides in order to divert to their own accounts some of the funds that were going to physicians, chiropractors, and physical therapists.
Herbicides, as we know, have some serious side effects on the environment but there are two "non-toxic" categories of weed killers. These are corn gluten weed killers and something called a weed eraser.
Corn Gluten Weed Killer
Corn gluten works as a pre-emergent weed killer by preventing the weed roots from developing. It should be applied in early spring and again in early August. The cornmeal will also act as a nitrogen fertilizer. It is effective against most garden and lawn weeds and safe, since it is made from that All-American grain: corn. What will the corn industry think of next? Soon we will control our lawns with a corn-based weed killer and then mow the lawn using a corn-based fuel.
To find out more, you can visit the Iowa State University Department of Horticulture Corn Gluten Meal Research Page.
The weed eraser works differently. Made from pelargonic acid, which is a fatty acid found in grapes, apples and carrots, it works by lowering the pH level quickly. It is enough to kill broadleaf weeds such as the dandelion and pigweed. Weed Eraser kills any green leaf on contact but is not transmitted to other plant parts. Results take minutes. Sounds like you would have to be very careful where you sprayed this.
There is an article on weed eraser on the National Gardening Association web site.