Is there a safe alternative to Roundup?
Update 3/23/15 -- Glyphosate, the active ingredient in Roundup, has been classified as a probable carcinogen by the International Agency for Research on Cancer. Details here.
Roundup® is touted as a safe, environmentally friendly and easy to use herbicide. It’s also denounced as a toxic, hazardous chemical. Which is right? Are there any alternatives to using Roundup?
Roundup® is a broad-spectrum herbicide, meaning that it has negative effects on nearly every plant with which it comes in contact. It is used for spot treatment of gardens, lawns, paved areas, and some agricultural crops. Although it is toxic, the active chemical, glyphosate, binds with soil. This means that glyphosate that comes in contact with the ground will not run off into water systems and becomes inactive. The substance also appears to be mostly nontoxic for mammals, including people, who eat food which was near plants treated with Roundup.
However, when glyphosate reaches rivers and streams, it is very toxic to aquatic life. Glyphoste can travel to waterways if it falls on asphalt or blows away on the wind. In addition, glyphosate is not the only chemical in Roundup®, simply the only one considered “active” by the EPA. The EPA only requires herbicide manufacturers to provide proof that the “active” ingredients are safe for the environment, not “inactive” or “other” ingredients. Herbicide manufacturers are not even required to list non-“active” ingredients on their packaging.
Polyethoxylated amine (also referred to as POEA or polyethoxylated tallowamine) is a surfactant, a chemical used to transport glyphosate from the leaves of a plant to the roots in Roundup®. POEA has been shown to be significantly more toxic to aquatic life—including algae, frogs, shrimp, and fish—than glyphosate. POEA is not trapped by soil like glyphosate and stays in the environment longer before degrading, creating an environmental hazard. In addition, recent studies indicate that the POEA in Roundup® may be toxic to human embryos.
Alternative products exist which play the same role as Roundup® in weed management. Acetic acid, fatty acids, and essential oils can all act as herbicides.
Acetic acid, or vinegar, can be sprayed on weeds to “burn down” the plant. When sprayed on plants, it causes chemical burns which eat away at the foliage until there are no leaves remaining. On the downside, any plant the vinegar touches will be affected, so if the spray blows into your garden, it will hurt your vegetables. Also, the vinegar only attacks the leaves. It doesn’t contain a surfactant like POEA to carry it into the roots, so the weeds may grow back within a couple weeks. On the upside, the vinegar will quickly break down in the soil and water, meaning it won’t contaminate your lawn long-term and is safe to use near water or pavement. Acetic acid may even be safe to use in lake sediments against invasive plants, although this application is still being tested.
Certain fatty acids, often in the form of soaps, are presented as safe alternatives to Roundup®. The solutions work like vinegar (and often contain vinegar as an additive) insomuch as they burn the leaves of the plant. Soon after the first application, the soap becomes inactive, so it only works for a very short amount of time, and the weeds may return. The most common fatty acid, pelargonic acid, is considered to have very low toxicity and to be environmentally friendly. However, the other ingredients in commercial herbicides are just as important as the active, so before buying any herbicide, make sure to look at the inert ingredients!
Essential oils—such as clove, peppermint, pine, and citronella oils—have been growing in popularity as herbicides over the last several years. They operate like vinegar and soaps, wherein they burn the foliage, but not the roots unless surfactants are added. Unlike the other two, essential oils often are not fully effective because of the way they are introduced to the plants. A portion of the oil will evaporate away or become inactive in the soil before it has interacted with the plants. Most essential oils are not know to have the severe effects of Roundup® in aquatic ecosystems, but each oil has its own potential harms and benefits, so care should be taken when applying it.
If you are thinking more long-term about your landscape, there are other options for weed control. If the tried-and-true method of pulling weeds by hand just isn’t working for you, but you don’t want to spray chemicals all over your yard, consider rethinking how you maintain your lawn. Adding corn gluten, appropriate plants, or lasagna mulching to your routine can reduce the number of weeds in it and make it easier to maintain.
Corn gluten is a byproduct of producing corn starch. It comes as a dry powder and must be applied to the lawn at least twice a year to be most effective against weeds like dandelions. It does not kill mature plants but will hinder the growth of new ones. So it is safe for gardens and will even add nitrogen to the soil, fertilizing the established plants. Corn gluten is safe for people and pets; it is a common ingredient in dog food. So what’s the downside? If you have hardy, well established weeds, corn gluten won’t do you any good.
The most appropriate plants for your yard are often native to the region. Planting native flowers in a garden or grasses in your lawn can help reduce the number of weeds because they are better able to compete for nutrients, water and light. Or, if you feel your yard is beyond hope and are willing to give up your grass, consider planting native ivy or moss in its place. Or perhaps even a garden!
If you want to start a new garden or tame your current one, consider lasagna mulching. The process involved covering the ground with newspaper, leaves, and other compost ingredients in layers, smothering your weeds and enriching the soil over the course of about six months. For more information on lasagna mulching, visit this page.
If you decide to use alternative chemicals for gardening, here are a few tips to help you out this summer:
- Try not to buy products which do not list all the “inert” or “other” ingredients on the label. If the company isn’t willing to share its product information, there’s a chance that there is something there you don’t want to see. The EPA provides a list of minimal risk, or list 4A, ingredients approved for pesticide use. Under a previous rating system, the ingredients were classified into risk categories: List 1 indicated high risk, List 2 indicated potential risk, List 3 indicated unknown toxicity, and List 4 indicated minimal toxicity. Lists 1 and 2 can be found on the EPA website for reference.
- Ask your lawn care provider if they can use natural products instead of Roundup® on the lawn. Many will use Burnout II, which is a clove oil product, or something similar when asked.
- Always follow the directions on the label. Just because a chemical is natural or organic doesn’t mean it isn’t dangerous. Just like onions and hot peppers can make you cry, acids and oils can cause burns when used incorrectly.
- Never use an herbicide before it rains unless specifically directed to. Even if the main ingredient doesn’t wash away, other ingredients may!
- Always read the warning on the label. The EPA has three warning levels: Caution, Warning, and Danger. If a product is labeled Danger—or even Warning—think twice before using it on your lawn or garden.
- When in doubt, ask an expert. Talk to your local greenhouse, lawncare company, Extension Office, or college horticulture department. Or, to find safety information about a chemical or product, look for the Material Safety Data Sheet (MSDS) online. These can be found for free, and you should never have to sign up to see them. There will be a lot of technical information, but it will also tell you whether the substance will be dangerous to your body or the environment.
- Use other good-care practices for your lawn. Don’t cut your grass too short, for example.
- Keep your ears open for any new information on the safety of natural herbicides. Although they have been tested for safety, they have not been examined with as much scrutiny as Roundup®, and should be treated with care.
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