An Article that Every Gardener Needs to Read
Roundup is a herbicide produced by Ortho, a division of the Monsanto Company. It is a glyphosate-based non-selective herbicide for the control of actively growing grass and weeds. Essentially, it kills all plant life on which it is applied. Note: Because glyphosate is not produced naturally, Roundup is not acceptable in an organic garden.
Roundup is hailed as a safe solution to weeding problems. Indeed, it does have many advantages. Roundup is sprayed on leaves and stems – the parts of the plant above the ground. It is then distributed throughout the plant. Glyphosate, the active ingredient in Roundup, inhibits an enzyme that produces amino acids essential for plant growth and life. Wilting and yellowing occur one week after application, while a complete kill comes in two to four weeks. There are a few primary advantages that the advertisers of Roundup emphasize. First, Roundup binds to the soil and will not spread to the water supply or other plants. Second, Roundup is broken down into “natural materials” by soil microbes (the microbes are unharmed in the process). Third, Roundup has a low toxicity level: According to laboratory tests, “Glyphosate does not cause adverse health or migrational changes in fish, and has no effect on aquatic or terrestrial invertebrates or water fowl, when used according to label directions.” (This information was provided by Ortho) Additionally, studies indicate that table salt is twice as toxic as glyphosate – 5,600 mg of glyphosate per kilogram of body weight killed 50% of rats tested, where one half of that dosage in salt (3000 mg per kilogram of body weight) was enough to kill 50% of a second test group. These advantages make Roundup seem to be a product that is highly safe and environmentally sound enough to be used in an organic garden.
But consumers, do not be deceived! There is a malevolent side to Roundup’s image as the perfect herbicide. First, glyphosate does not break down quickly. It takes 45 days for half of the chemical to degrade, and 6 months for 90% to degrade. It may take up to two years for the glyphosate to degrade entirely. During this time the chemical would be present in the soil in quantities significant enough to rule your garden out of the organic classification. In other words, after a single application of Roundup you will be unable to call your garden “organic” for up to two years.
There were 4 Roundup Products at the garden supply store:
(Click on the links below for a picture and description)
I called Ortho and asked them to send me some information on Roundup. According to the information that I received, “Ornamentals and flowers may be planted or seeded 1 day after applying Roundup. Edible crops listed on the [product] label may be planted from transplant or seed after 3 days. If a crop is not listed on the label, wait 30 days before planting. (Note: Wait 30 days for tomato transplants).” I visited my local garden supply store and, to my astonishment, of the four Roundup products present, only one (the Roundup Concentrate Weed and Grass Killer) had the additional information for planting edible crops. I wondered if there could be a reason for the absence of this important information on the other products (Ready-To-Use Weed and Grass Killer, Roundup Pull ‘N Spray, Roundup Sure Shot Weed and Grass Killer). Perhaps only concentrated solutions of Roundup were dangerous. Interestingly enough, when the concentrated Roundup is diluted according to the attached instructions, its concentration is lower than the products that are ready to use. After dilution, Concentrated Roundup is weaker than the ready to use Roundup products (the concentration of glyphosate in the ready to use products is 0.96%; the concentration of diluted Concentrated Roundup is 0.84%). Why is the edible crop information pertinent for the Concentrated Roundup and not pertinent for the other Roundup products (which are applied in stronger concentrations than the Concentrated Roundup)? I have a potential answer: Ready to use Roundup products outsell Concentrated Roundup products. Why should Ortho deter valuable customers with 30-day waiting periods? Why not simply exclude this important 30-day warning and say that planting can occur “1 day after application?”
With the exception of the Concentrated Roundup Weed and Grass Killer, none of the other Roundup products at the store had the additional information on their labels. I’m not making this up; simply look at the labels on the Roundup website – the omission is obvious. For the three products that are ready to use, there is no reference to a longer waiting time for edible crops. There is no list distinguishing three-day crops from thirty-day crops. The only sentence in reference to planting after application is “Ornamentals and flowers may be planted or seeded 1 day after [the phrase ‘1 day after’ appears in bold on all Roundup products] applying Roundup.” This omission is deceptive. The consumer is led to believe that it is safe to plant 1 day after Roundup is applied, when, in fact, there are many crops that should not be planted until 30 days have past. Among these are tomatoes, the staple of the home vegetable garden.
I was then led to the next logical question: Why should tomatoes and other crops not be planted until 30 days after an application. Perhaps the people at Ortho think that glyphosate has the potential to harm people when ingested. That is the logical inference; after all, why can ornamentals and flowers (which are not eaten) be planted twenty nine days earlier than tomatoes and other edible plants (which are eaten)? Is there something that Ortho is not telling us? Does Roundup have the potential to do harm, despite the toxicity results and their assertion that it “only affects plants?” Or, is Ortho simply not 100% sure that glyphosate is safe to consume in small quantities? These questions are legitimate and raise serious concerns about the confidence (or lack thereof) that Ortho has in their own product (If it is truly safe and “only affects plants,” then why is there a need for caution.)
The Roundup label reads “Any product not absorbed by plants breaks down into natural materials.” What are natural materials? According to the information I received, “the breakdown products are water, nitrogen, carbon dioxide, phosphorus and carboxylic acid.” I interviewed a colleague with a Masters in organic chemistry, and she said, “A carboxylic acid is a classification into which many different acids fit [carboxylic acids have a –COOH group]. A carboxylic acid is not a specific acid.” This discovery gives rise to more disturbing questions: Why is Ortho being vague and not naming the specific acid? Is there some insidious reason for an answer that is imprecise? Additionally, some carboxylic acids occur naturally and some do not. Are the carboxylic acids produced in the decomposition of glyphosate really “natural materials?”
Roundup breaks down to an unspecified acid. Maybe the acid is dangerous; maybe it’s not. Maybe the acid is naturally occurring; maybe it’s not. Regardless, an acid is an acid. As any accomplished gardener knows, soil pH is extremely important. Plants will only survive in a specific pH range (some gardeners add lime to the soil to raise the pH). As glyphosate degrades, it releases acid into the soil and lowers the pH. Roundup may bind to soil particles, but the acid does not. Acid is mobile in soil and rainwater, and it will lower the pH level of nearby streams, lakes (fish and other aquatic organisms also need a specific pH), and your entire garden.
I hope this article has raised some serious concerns about the use of Roundup in the yard and garden. Maybe some of my questions have reasonable answers from Ortho. Maybe some of them don’t have satisfactory answers. You, the consumer, need to decide if you are willing to take a chance and ignore all of these unanswered questions. Oh yeah, don’t forget the primary point of this article: Roundup is not a natural product, and can never be used in an organic garden.
I submitted my article to Ortho in three ways. On April 19th, 2000, I visited their website and submitted the article through their comment and question form. I sent a letter to their customer service department with the article and a brief explanatory message. I also sent a letter to Bruce Bickner, the Executive Vice President of the Monsanto Company. I have not received a response. If you have concerns about the safety/honesty of Ortho and Roundup, I encourage you to write to Ortho using their comment form.