Those of us lucky enough to live in Western Massachusetts sometimes feel at least partly insulated from global crises. Of course, our region is not immune to challenges. Fortunately, the creativity that makes us the envy of visitors helps us find solutions to problems.
Today’s column provides information vital to the well-being of our gardens and forests, and offers perspectives that may provide a broader view during an era when bad news can feel overwhelming.
Many gardeners are familiar with the beneficial impacts of earthworms. Yet there’s a notable exception, and local citizens can help thwart a destructive and invasive species known as jumping worms, a nickname given to Amynthas agrestis, a variety of earthworm.
Jumping worms have been in the U.S. for decades but are gaining attention due to their increasing numbers and a growing understanding of their destructive tendencies.
They’re like the billionaires of the worm world: jumping worms are shiny, firm, and clean-looking, but they’re up to no good. They wreak havoc in the dark, and squirm wildly when you try to get ahold of them.
It turns out that garden-variety worms — the slimy, dull-colored characters — are the ones you can trust. All earthworms are segmented and have a clitellum (a band or collar). Most local earthworms belong to the Lumbricidae family, but jumping worms belong to the Megascolecidae family.
Worry not, dear readers: despite two Latin terms in the preceding paragraph, there will not be a test. Please keep reading, because you can make a difference when it comes to jumping worms. While we’re not likely to eradicate the pests, we can mitigate their spread and limit the damage they do to local forests, parks, and gardens.
UMass Amherst’s Center for Food, Agriculture, and the Environment recently published two fact sheets about the spread of invasive earthworms, noting that jumping worms alter soil qualities, particularly in forested locations, and may even trigger changes that favor invasive plants in forest under stories. Find the fact sheets online: https://bit.ly/2WbW3PQ.
Some of the biggest impacts of jumping worms are evident in forest ecosystems. According to the UMass fact sheets, jumping worms consume the upper organic layer of soil, which can lead to erosion and nutrients being leached from the soil. This can have broader implications, because changes in forest soils can result in alterations in understory species composition in favor of invasive flora and fauna.
Jumping worms can consume a critical layer of organic matter that also supplies nutrients vital to wildlife. Recent reports indicate that the worms cause reduction in the amount of leaf litter on the forest floor.
In addition, locals have noticed mulches rapidly disappearing from home gardens, including piles of wood chips decreasing unusually fast. The mystery is solved once jumping worms are spotted and identified.
UMass fact sheets assure citizens that jumping worms are not directly harmful to people or pets, despite the fact that they thrash wildly when disturbed, reminding people of snakes.
For Amy Pulley, proprietor of Wing and a Prayer nursery in Cummington, the discovery on her property of one jumping worm in August “utterly changed my life. I cried when I saw it, and immediately wondered if I’d have to close my nursery. But I’ve learned mitigation techniques and, at this point, just want to keep the worms out of my pots. It’s all about damage control.”
Pulley and other local horticulturists believe that the arrival of jumping worms brings a message. “It’s one of many planetary changes that makes us wonder about the implications of our actions and habits. It’s humbling. I feel it’s best to take a long view.”
Her fervent hope “is that people will take this in. Jumping worms represent a change I never would have chosen. But they’re here, so let’s be curious about what else we may be overlooking?What’s happening to our lands and bodies? We have to educate ourselves and take measured, intelligent approaches.”
Spoken in the midst of a global pandemic, Pulley’s words carry particular weight. But instead of getting lost in musings, she learns strategies and takes action. She emphasized that people who notice jumping worms in soil, compost, mulch, and potted plants can respond with simple steps.
Covering a compost pile with plastic in order to heat materials to 104 degrees for up to three days can kill egg-containing jumping worm cocoons. Gardeners can also prevent the transit of jumping worms from one part of their property to another by not moving plants from an infested area to a non-infested area.
“Gardeners and property owners can clear out as many jumping worms by hand as possible,” said Pulley. “They’re found close to the surface, as opposed to other earthworms, which burrow more deeply into the soil.”
Pulley’s recommendation echoes advice from UMass: “Remove jumping worms when you see them. Simply seal them in a bag and throw it in the trash — they won’t survive long. Reducing the adult population will eventually reduce the number of egg-carrying cocoons in the landscape.”
UMass information indicates that jumping worms may also be disposed of into a bucket of vinegar or soapy water.
Another measure, according to Pulley, is to cover a plot of soil with clear plastic so it heats to at least 104 degrees Fahrenheit. “Contrary to popular belief, clear plastic is better than black plastic,” said Pulley, “because it raises the temperature higher.”
Experts warn gardeners not to try to manage the worms with chemicals, as there are currently no approved substances designed for that purpose.
“I see glimmers of hope in terms of people understanding our ecosystem,” said Pulley. “When I opened my nursery seven years ago, most people didn’t know what I was talking about when I spoke about the importance of pollinators and native plants. But something has shifted in the culture.”
Pulley noted that over the last three or four years, customers have been bringing comprehensive lists of favorable host plants and native varieties. “It’s heartening,” she said. “Local groups are doing a great job of educating, and it’s paying off. Many more people recognize that we’re part of this earth and must feed and nurture other creatures instead of destroying them.”
Pulley works not only to keep her plant stock clean of jumping worms and their cocoons, but to educate others. “I feel residual grief, knowing that I unwittingly must have sold plants that contained jumping worms or their cocoons. But I had no idea at the time, and all I can do is go forward.”
Given that our region is experiencing a significant outbreak of jumping worms, Pulley and others are determined to spread the word about facts, mitigation techniques, and broader implications.
“If you find you have jumping worms, don’t share your mulch or compost,” said Pulley. “If you wish to share plants, wash the roots carefully and replant in sterile potting soil before selling or giving them away.”
One difference between jumping worms and other kinds is that beneficial earthworms can live up to ten years and survive our winters by burrowing deeply and waiting out frigid temperatures. Conversely, mature and juvenile jumping worms are not cold tolerant and die within a year. The crux of the problem, however, is that their cocoons can overwinter, allowing the next generation to hatch in the spring.
Unfortunately, jumping worms are difficult to notice in the spring. Cocoons are small, eggs are about the size of a poppy seed, and the immature worms can be tiny. They become noticeable — if searched for— in mid to late May.
UMass fact sheets point out that the first adult jumping worms appear by the end of May or early June, but numbers are low and infestations are rarely noticed at that time. Apparently, it’s easy to misidentify them early in their life cycle. Most observations of fully mature jumping worms occur in late summer.
To spot jumping worms, look for critters that are smooth, glossy, and dark grayish brown in color. A mature jumping worm is 4-5 inches long, with a clitellum that’s cloudy-white to gray in color, unlike the pinkish clitellum of beneficial earthworms.
Another key identifier: in jumping worms, the clitellum is flush with the rest of the body and wraps completely around, unlike in a beneficial earthworm, where the clitellum is raised and wraps only partly around the body, like a saddle. And in jumping worms, the clitella are found closer to the head than those of beneficial earthworms.
UMass sources note that “mature nightcrawlers can be 6-8 inches in length, and have thick, slimy, and floppy bodies. They wiggle and stretch when disturbed, and do not tend to thrash violently or move in a snake-like manner. They can be perceived as slow and sluggish compared to Amynthas spp. [jumping worms]. ”
Colrain resident Elizabeth Erickson, certified in 2017 through the Western Massachusetts Master Gardener Association, said that although she’s found jumping worms in her home gardens, she hasn’t witnessed noticeable damage. Yet she understands their destructive potential, “especially to forests,” and no longer shares plants from her land. “It’s sad, because I’ve always loved to share plants. But we must take care not to pass these worms around.”
Erickson and fellow Master Gardener Kendall Clark paused in their work recently while volunteering in the Energy Park gardens in Greenfield. They call themselves ecogardeners. “Our 2017 Master Gardener class was the first with a strong environmental focus,” Erickson said.
Clark, who lives and gardens in Conway on the South River, has also stopped sharing plants. “So far, my garden is doing okay. But I see the proliferation of jumping worms — like everything else that’s happening in the world — as a call to adapt. For instance, I’m moving away from using wood chips, which jumping worms love, and instead focusing on using green mulch.”
Green mulch is not mulch in the traditional sense; it’s not applied as a separate material, like straw or wood chips. “Instead, I grow ground covers, thickly planted, and opt for native plants. I try to emulate nature.” Erickson echoed Clark’s suggestion, saying that she plants radish and buckwheat as ground covers.
Clark and Erickson discussed whether climate change could be a factor in the proliferation of jumping worms. “It’s possible,” said Erickson. “For a number of reasons, forests in the Midwest are being significantly damaged. Even around here, some wooded areas don’t look healthy. We see lots of invasive plants, like multiflora rose, bittersweet, and honeysuckle.”
Clark added: “I suspect climate change factors into the problem. Forests are suffering due to jumping worms as well as increased deer browse. We humans easily forget that we’re part of a larger picture, a whole ecosystem. Everything is related.”
Discovering jumping worms on her property was a shattering experience for Clark. “I felt despondent,” she said. “It was a horrible feeling, like learning that I had ‘Garden VD’ or something.”
She said that even if people think they don’t have jumping worms, “they probably do. The worms are here, and we need to learn to live with them. We’re not going to stop gardening. In fact, I feel like we’re gardening in order to help save the planet.”
Gardeners can look carefully around their property after a heavy rain, said Clark. “That’s when the worms are most evident.”
Erickson and Clark feel strongly that choosing native plants is part of the solution. “Not only do native plants attract wildlife like hummingbirds and many pollinators, they also put us in better balance with nature,” said Erickson, a retired physician’s assistant.
According to UMass sources, since jumping worms have been in Western Massachusetts for decades, there’s no need to report them, even though they’re gaining attention.
People who learn to identify jumping worms can help others do so, as well. This applies not only to gardening, but recreational fishing. The more people who know not to purchase jumping worms for composting or for bait, the better the outcome.
“Jumping worms are like a COVID of the worm world,” said Clark. “If we pay attention, work well together, and learn some lessons, we’ll get through it.”
For those who want more detailed information, an online symposium is planned for January. (There will be a fee.) Check UMass events: https://ag.umass.edu/upcoming-events in November.
Eveline MacDougall is the author of “Fiery Hope” and an avid gardener. She has learned to identify jumping worms and has dispatched quite a few in soapy water. She welcomes feedback and tips about other column topics: eveline@amandlachorus.org