Live and let live

This month Bayer agreed to pay $10 billion to people who’ve developed cancer after using Monsanto’s herbicide Roundup. Bayer plans to continue selling Roundup and still insists that it’s safe to use. The record settlement suggests otherwise. And there’s a huge environmental drawback to Roundup that doesn’t get enough attention: loss of biodiversity.

    The active ingredient in Roundup is glyphosate, which blocks the action of an enzyme that allows plants to make a necessary amino acid. 

Roundup at Home Depot

Roundup has been around since 1974, but it became a huge moneymaker in 1996 after Monsanto introduced Roundup Ready crops. These are patented genetically modified plants in which the target enzyme isn’t affected by glyphosate. More than 90 percent of US soybeans are now grown from these genetically modified seeds. Roundup is so ubiquitous that super-weeds have developed resistance to glyphosate.

Soybean field, Pennsylvania-photo Jakec

    When my garden was young, I remember being taught that while other herbicides might be dangerous, Roundup was perfectly safe. The idea was that it breaks down so fast that residues in plants and soil wouldn’t be a problem (not true).

    The most important reason to avoid Roundup, I think, is that spraying weed-killer in yards or on agricultural fields eliminates a huge reservoir of native plants—the weeds—that native insects depend on. A good example is the loss of common milkweed (Asclepias syriaca) that monarch butterfly larvae depend on. With widespread Roundup spraying, monarch populations have plummeted. 

Monarch nectaring on common milkweed

     Full disclosure: I once tried spraying Roundup when I saw the notoriously aggressive groundcover goutweed (Aegopodium podagraria) spreading around plants I’d received from a friend’s garden. 

Goutweed can easily get out of control

I planned the Roundup application for a sunny fall day. It took me two hours, because I was so fearful. I put on old clothes and sneakers, disposable gloves, goggles and a mask. 

 

I wished I had this much protection when spraying Roundup

I covered the surrounding plants over a radius of at least a yard with rags, then I carefully sprayed Roundup, trying my best to wet only the goutweed foliage. Then I had to remove the rags and protective gear and throw my clothes into the washer.

     Was it worth it? Not at all. The goutweed never missed a beat. Perhaps I’d applied Roundup too late in the season when the plants had stopped growing. The next spring, I weeded the goutweed out of the bed, taking extra care to dig out its slender roots. It never reappeared.

     As nonnative invasive plants became a focus of concern, Roundup was touted as a solution. Painting Roundup on cut stems of bad actors like Japanese knotweed (Polygonum cuspidatum) is still recommended. That’s understandable, because the plants are virtually immortal. I tried it once with no effect. The knotweed sprouted again the next spring. For my purposes, the benefits of Roundup definitely don’t outweigh the risks. Now I prefer the idea of hiring a flock of goats to eat knotweed thickets.

A goat clearing invasive plants at Travis Air Force Base-U.S. Air Force Photo by Heide Couch

 
     If we had a functioning federal government, it would ban glyphosate as well as neonicotinoid insecticides. Us against them isn’t a sustainable way to think about natural systems.