You are considering using an herbicide, but are concerned about its effect on your pets and young children. You can learn much about the safety and efficacy of a weed killer by understanding its components.
Read the Label
According to Mother Earth News, commercial herbicides typically have "active" and "inert" ingredients. While pesticides comprise the "active" ingredients, manufacturers list the "inert" ingredients as a percentage.
The Environmental Protection Agency (EPA) defines an inert ingredient as "any substance other than an active ingredient, which is intentionally included in a pesticide product. Inert ingredients play a key role in the effectiveness of a pesticidal product." For example, inert ingredients might include surfactants that enable the pesticide to adhere to the weed surface and solvents that keep pesticide dissolved in solution.
Inert Does Not Mean Inactive
Mother Earth News claims that inert ingredients are anything but harmless. Although herbicide manufacturers aren't required by federal law to disclose inert ingredients, some used in commercial weed killer are highly toxic.
Typical "inert" chemicals can include 2,4_D, carbon tetrachloride, chloroform and chloroethane -- all carcinogens.
If you seek endorsements of pet and child friendly weed killer from prominent organisations such as Organic Gardening, Yankee Magazine and the National Audubon Society, you probably won't find them. Many of these organisations recommend an ounce of prevention, some old-fashioned weeding or a homemade weed killer.
Choose a Weed Killer With Household Ingredients
There are non-toxic weed killers available that incorporate household ingredients with old-fashioned gardening wisdom.
Vinegar (any type) is a natural dessicating, or drying, agent. When sprayed on a weed, it kills by drying out the leaves first. After one or two applications, the roots die by starvation. Typically, household vinegar has a 5 per cent concentration; organic gardening vinegars available in gardening centres usually have a concentration of 10 to 20 per cent.
Corn meal gluten, a pre-emptive agent, works by making soil conditions unsuitable for weed growth. It is available in most gardening centres and works best when added to the soil early in spring. Regular cornmeal works just as well.
Salt water also is a dessicating agent. When added to the soil, dry salt sterilises it and makes it unsuitable for all plant growth. Salt water should be used sparingly--painted with a brush only to the weed surface or in patio, sidewalk or driveway applications.
Sugar, like dry salt, makes soil conditions unsuitable for weed growth. Throwing a pinch in the soil or added as sugar water, pushes soil microbes into overdrive.
Homemade weed killers made with clove, citrus or chilli pepper oils increasingly are available in gardening stores. These make effective herbicides that are safe for children and pets.
Although household vinegar is tasty lightly spritzed on salad greens, at higher concentrations, it can cause skin irritations and temporary blindness. Use with caution.
Some ingredients categorised as organic or natural, are not safe around pets or children. For example, borax (sodium tetraborate), used in small concentrations is effective as a weed killer, especially for hearty weeds like the Creeping Charlie. However, it's not safe if ingested by pets and small children, according to GardenGuides.