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Crazy snake worms are not on the plane — but they may well be in New England gardens

An adult crazy snake worm slithered in mulch.
An adult crazy snake worm slithered in mulch.(Josef Görres)

Crazy snake worms are slithering into gardens across New England, and they mean big trouble, experts say.

Yes, that’s their real name. (Their scientific name is Amynthas agrestis.)

The gray worms, which can grow up to 8 inches long, are known for wildly thrashing their tails, which often detach as the worms attempt to escape capture.

Experts are warning that they’re not just unattractive, they’re an invasive species that is damaging the region’s gardens and woodlands.

While the common earthworm improves soil quality by burrowing into tunnels in the dirt that aerate the soil, crazy snake worms eat through the “duff,” or leaf layer, that covers the forest floor.


“By eliminating duff and altering soil composition, crazy snake worms are changing the plant communities in New England,” Brendan Keegan, a landscape crew gardener at Harvard’s Arnold Arboretum, said in a blog post last fall on the Arboretum website. “The soil conditions they create favor non-natives over native species, making it less likely for many native plants to survive.”

First reported in California in 1862, they came to the United States from East Asia, said Josef Görres, associate professor in the Department of Plant and Soil Science at the University of Vermont.

In 1947, they were being grown in a tank to feed platypuses at the Bronx Zoo, and by the 1980s, they had made their way into the forests of New England, Görres said. They’re often used as live fishing bait.

In home gardens, they can eat through mulch and cause soil to be too loose for plants to establish firm roots, Görres said.

“Last year, I was growing eggplant in my garden and I had these [crazy snake worms] as well. When the eggplants were maybe a foot and a half tall, I could just pull those plants out. They weren’t sticking in the ground anymore,” Görres said.


Görres believes that climate change is to blame for the crazy snake worm population getting out of control. The worms like warmer weather, he said, and have thrived as the growing season has gotten longer in recent years.

For home gardeners, one remedy Görres recommends to keep the worms at bay is to mix an ounce of dry mustard in a gallon of water and apply it to worm-infested soil. The solution will cause them to come to the surface, at which point they can be plucked out and placed in a bucket of soapy water to meet their end.

But Görres thinks it’s nearly impossible to keep crazy snake worms out of gardens for good — you’d have to repeat the process every year, and make sure your neighbors are doing it, too.

If your yard is already infested, it’s best not to dispose of yard waste at the dump, where the worms can easily spread, he noted.

Is there any hope left for New England’s gardens? “We’re trying out microorganisms like fungi that can kill these worms,” Görres said. He and his colleagues will begin testing a potential solution this summer.

Margeaux Sippell can be reached at Follow her on Twitter @MargeauxSippell.