As soon as I saw the June 28 Press Herald story on the town of Falmouth using glyphosate to combat invasive plants, I knew reaction would be strong.

Glyphosate – the prime ingredient in Roundup (which is made by Monsanto) and other widely used herbicides – has been linked to health and environmental problems. The World Health Organization has said glyphosate is “probably carcinogenic.” Other studies have linked it to kidney and liver failure, promoting the growth of cancerous cells in breasts, premature aging, reproductive failure, immune system failure and birth defects.

Invasive plants – multiflora roses, bittersweet, honeysuckle and Japanese knotweed – are also seriously problematic. Because they come from distant lands, invasives have no local enemies (i.e., animals that eat them), so they spread quickly. They crowd out native plants, which have developed locally over thousands of years to support the complicated web of animals, birds and insects that together make up the local ecosystem. The consequences can be dire, among them:

Native species can’t find enough food or the right food, nor can they find suitable places for dens and nests to raise their young;

Monarch butterflies starve; and

Native pollinators sicken, infected by diseases carried by invasives.


All of which raises the question: Is the cure (glyphosate) worse than the problem (invasives)?

After talking with a handful of experts and several involved in Falmouth’s spraying program, my own answer is a qualified no. Used conservatively and applied by people who follow label directions, herbicides – even Roundup – have their place, such as when communities are faced with invasive and ever-expanding jungles.


Jessica Shade, director of The Organic Center, which monitors studies of links between health problems and many different chemicals, said the links between glyphosate and health problems are mostly statistical, with no studies showing how the pesticides cause diseases. Most of the studies look at people who have eaten genetically modified Roundup-resistant crops. And even those studies recommend that more studies be done.

“The problem isn’t the chemistry,” said Bob Shafto, Falmouth’s outdoor ombudsman who oversees the town’s spraying program. “It’s the way (the herbicide) is being used in agriculture, where they’ve got miles and miles of fields of corn being sprayed instead of cultivated, and the spray kills all the sources of food for pollinators.”

Jeff Taylor of Vegetation Control Services, the company that applies the herbicide for Falmouth, says that his workers follow all label instructions, avoid areas near homes where residents don’t want spraying, use an anti-drift method of spraying, and stop if the wind rises. The town is applying Rodeo – a glyphosate product that, unlike Roundup, can be used near water safely – as well as an aquatic-approved surfactant to help the chemical stick to plants.


The state agencies charged with managing invasive plants and pesticides defend the Falmouth program.

Spraying with glyphosate “can be an appropriate treatment for dealing with invasive plants, depending on the goals of the property owner,” said Nancy Olmstead, invasive plant biologist for the Maine Natural Areas Program in the Department of Agriculture, Conservation and Forestry.

As for the Board of Pesticide Control, which under board policy answers questions only by email, it said that Falmouth’s methods are appropriate as part of a program to remove invasive species, as long as the areas are replanted with species that will survive there.


There is plenty of disagreement on that point. Just because government agencies find the chemicals appropriate for use doesn’t mean they are safe, The Organic Center’s Shade countered.

“A lot of the chemicals haven’t actually been used that long, and there haven’t been a lot of broad-scale studies,” she said. “A lot of these chemicals don’t have an immediate effect, so who knows what happens over time? They used to spray DDT throughout neighborhoods and think it was safe.”


And Eric Sideman of the Maine Organic Farmers and Gardeners Association noted that glyphosate is toxic by definition, and people should avoid using toxic substances. “Roundup is essentially a labor-saving device,” he said. “We would hope the people on their own property would continue mowing, cutting or hand pulling the invasive plants” rather than use toxins.

You cut down the invasives and keep cutting them so that they neither produce seeds nor grow more than 4 inches tall. The plants will expend energy sending up shoots, but the leaves will not bring in enough energy to feed the roots. Eventually, Sideman said, the roots will use up all their stored energy and the plants will die.

People have eliminated poison ivy using this methods, he continued – although poison ivy, while an evil plant if you ask me, isn’t an invasive; it’s a native.


Last winter, I attended a talk on removing invasives without using chemicals given by Lois Berg Stack, an ornamental horticulture specialist at the University of Maine Cooperative Extension Service. She admitted that when she first moved into her home, she used Roundup – but said she wouldn’t do so again if she were moving in now.

I have used Roundup in my own garden, but I don’t plan to ever do so again either. I am increasingly concerned about pesticides, plus the invasives in our garden are under control (and we are never moving!). Setting my own yard aside, cutting out invasive plants and killing them by continued cutting is well within the ability of homeowners. However, dealing with giant invasive patches along roads in communities may be a different question. It involves worker safety and tax dollars. Life is a balance of what you want to do and what you can do.

And now there are goats. During her talk last winter, Stack recommended goats, who cheerfully munch on, and eliminate, invasives. At that time, there was nowhere to rent a goat in Maine In a July 6 Press Herald story, though, I read that a woman has launched a goat-rental operation.

Now we’re making progress.

Tom Atwell has been writing the Maine Gardener column since 2004. He is a freelance writer gardening in Cape Elizabeth and can be contacted at 767-2297 or at: [email protected]

Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.

filed under: