Snake worms

The crazy jumping snake worm is no friend to the environment.

As gardeners, we know how wonderful worms are. Their castings make excellent soil amenders and they are great little aerators.

But, none of this praise can be attributed to a new kid on the block — the crazy jumping snake worms.

There is literally nothing good about these buggers, and we have them in our forests, lawns and gardens. They gobble up the duff and leave behind castings that are not rich in beneficial nutrients, but full of heavy metals from industrial sources. It’s not even advisable to feed them to chickens.

The name crazy jumping snake worm (Amynthas agrestis) refers to their thrashing and flailing when disturbed. That’s the jumping. Snake comes from their locomotion. Rather than move with an expand-contract motion, they slither side to side like a snake. Flip them belly up and they will instantly flip back over.

Other than vigorous animation and a distinct white band around their necks (the egg cocoon), these worms look just like common earthworms. Most gardens in Vermont are already infested with snake worms, but gardeners unknowingly assume they are common earthworms.

To be sure, take a closer look at the soil. Is there a lovely consistency to the duff, like a year’s worth of coffee grounds had accumulated?

Those coffee grounds are an astonishing layer of snake worm castings, wherein lies the problem. Although the worms don’t directly harm plants, their several inches of worm castings do. They loosen and aerate the soil to the point that roots have nothing to latch onto and they dry out.

Snake worm castings can alter a forest soil structure so that it can no longer support the seedlings of trees and understory plants. That leads to woodland thinning, less food for browsers, vulnerability of ground-nesting birds, disappearance of ephemeral wildflowers. And on it goes.

In most of Vermont

I learned about snake worms at a seminar where Dr. Josef Görres, a professor of soil science at UVM, was the presenter. He has been studying snake worms for several years, and his research shows that Vermont’s highest population of snake worms is in Windsor and Chittenden counties, but he has found them everywhere in Vermont, except the Northeast Kingdom, Orleans and Essex. They are prohibited in New York and are a restricted species in Wisconsin.

Snake worms come from Japan and the Korean Peninsula and probably arrived in the U.S. in horticultural products. Experts suspect they might have been transported in the root balls of cherry blossom trees in 1912 as a gift from the people of Japan to the people of the United States.

Snake worms lay eggs from July through November. The worms die in winter, but the eggs, which are the size of a small peppercorn and hard to see without a magnifying glass, can survive up to 40 degrees below zero Fahrenheit for up to two years.

Each worm can lay an average of 60 eggs per season. Do the math and weep.

Listening to Dr. Görres was like listening to a horror story podcast. Once I comprehended how bad these worms are, I came home and inspected my gardens. What I discovered was devastating; my despair was crushing.

I had coffee-ground soil in every single garden. I thought of all my years of hard labor and financial investment.

I stomped and swore.

I even cried, but mostly I thought of everything I had done right.

I had tended my gardens well. They are prolific and beautiful and I enjoy them immensely. No one wants to see the object of their passion devoured by worms.

And just like that, I became a worm killer.

Take action!

According to Dr. Görres, the best line of defense is starvation. Don’t feed them!

That means no non-organic compost and no bark, leaf or straw mulch.

With all the poisons we have on the shelves, you’d think there would be something to treat them with, but no certified pesticides have shown any results. The best treatments are a solution of one-third cup ground mustard seed powder (spices.com for best prices) to 2 gallons of water, or plain old soap.

Like mustard seed, soap’s saponins are a skin irritant the worms can’t tolerate. The recipe: a few squirts of liquid soap to 2 gallons of water. Each 2-gallon solution covers about 2 square feet of soil.

Applying the solution is time- and labor-intensive. It takes two people, one to thoroughly saturate the soil and one to pluck the worms as they flail to the surface.

Do this in late May and again mid-August and you are off to a good start for eradicating them, temporarily at least.

If you buy horticultural products, make sure your retailer is aware of the worms and is buying from reputable wholesalers. For plants that you purchase or trade with friends, bare the roots and thoroughly soak them before planting.

Be vigilant, be determined. Save the world from snake worms.

More info: Do a web search for crazy jumping snake worms. You will find more than you care to know.


Kate Carter is a passionate gardener and the author of “Wildflowers of Vermont” and “Shrubs & Vines of Vermont,” available at Vermont bookstores.

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