Responses to GardenRant reviews of The Truth about Organic Gardening revealed very different attitudes toward Round-up – not just from our commenters but even between Elizabeth and myself. Most of us agree it SHOULD be avoided but then there are situations where we ask: "What’s the better alternative?" and no answer is forthcoming.
In the "It Could Be Worse" Camp
Here’s what Jeff Gillman has to say about Glyphosate, the active ingredient in the top-selling herbicide in the world, Roundup (made by the company we all love to hate – Monsanto).
After declaring that hand-weeding is always the best choice for the gardener and assuring readers that he’s NOT be a fan of synthetic herbicides, Gillman writes that "Glyphosphate and glufosinate ammonium are probably the safest herbicides to use when preparing ground for planting because of their ability to kill most weeds while maintaining a short life in the soil." They’re "relatively safe for humans and the environment if they’re used in accordance with their labeled instructions," though under "some easily conceivable misapplication scenarios, Roundup could have deleterious effects on the environment," especially to frogs, and that’s mainly because of the inactive ingredients (soaps and oils) that the glyphosate is mixed with.
Gillman goes on to explain the new rating system called the Environmental Impact Quotient (which assesses risk to farm workers, home consumers, and the environment) and urges their inclusion on all labels. Here’s what surprised me: The EIQ of Roundup is only 15.3 (on a scale of 1 to 100), compared to, say, organic horticultural oil, which has an EIQ of 27.5 because it can hurt beneficial insects and plants.
To Prepare for a Meadow
The earth-huggers at the American Horticultural Society first tried creating a meadow organically but ultimately prepared the site by using Roundup. The road to Roundup included first applying for permission from the county to do a controlled burn, a request that was turned down. Next, they tried preparing the meadow by tilling, but that only unearthed decades of pokeweed seeds. Finally, they used Roundup under carefully monitored conditions – no chance of rain, etc.
Gilman notes the exact same problem with tilling, adding that it also can cause erosion and make the ground susceptible to compaction. "So why not apply glyphosate and allow the weeds you’ve killed to work as mulch?" But others disagree and suggest instead that that black plastic is the best way to clear land of vegetation. Ah, but that method kills all the beneficial critters in the soil, though only for one season, I suppose (they’ll return with the application of organic matter). I remember hearing soil food web guru Jeff Lowenfels (author of Teaming with Microbes) declare his hatred for plastic because it destroys the soil-food web but wonder what he’d recommend instead. Roundup?
To Remove Invasive Plants
Another Roundup-related controversy arises from its widespread use to remove invasive plants. But even in the service of that universally accepted good cause, its use is criticized. Faith Campbell of the Nature Conservancy, for one, gets slammed for using it in the removal of invasive plants, despite her standing as a "rabid environmentalist" (and I SURE wish I remembered where I saw that characterization).
To Remove Hard-to-Get-To Plants
Cass Turnbull recommends it when you can’t dig something out – maybe because it’s in a rockery or has its roots entwined in a plant you don’t want to kill. She keeps small bottle of paste+brush containing Roundup in her pruning bag when she works.
I confess to a lack of purity in many things, including my adherence to strict organic practices. So when I discovered poison ivy coming up from beneath layers of other groundcovers, I squirted its leaves with the systematic herbicide that does the job. I think I’ve finally tackled the poison ivy population on my property but this season I plan to go after another hard-to-get menace – the creeping euonymus at the base of my big ole white oak. If there’s some other way of getting rid of it without endangering the tree and the other plants it’s entwined with, I’d love to hear it.
How Roundup Works
According to sources I trust, it does NOT poison the soil. It’s a systemic, which means it moves from the leaves you’ve just sprayed throughout that one plant and kills it. Nearby plants are not affected unless your aim is really bad, or it’s a windy day – and just DON’T DO THAT.
Also don’t get it anywhere near water, because it IS toxic to aquatic critters. And using it regularly to kill routine weeds? Ugh. Why not prevent weeds and when they grow despite your best mulching, just use a little muscle?
There’s a good summary of what’s known (and hated) about Roundup and its maker here on Wikipedia.