Invasive Asian Jumping Worm Population Soars in Its 100 Years in Maine

Although Maine has been fighting Asian jumping worms for almost a century, the state's current weather has led to an upsurge in the invasive species population.

100 Years of Invasive Asian Jumping Worms

Gardeners in Maine are facing a growing threat from invasive jumping worms, prompting a defensive response as their numbers surge across the state. Though present in Maine for a century, the Asian jumping worms were historically localized, primarily in southern and central regions. They have become much more numerous lately, which presents difficulties for gardeners.

These ravenous worms destroy topsoil layers and require different planting techniques because they are resistant to ordinary eradication measures and are born pregnant.

Jessica Seiders from Jefferson experienced a significant worm infestation, noting their prevalence in purchased soil and compost. Unlike beneficial earthworms, jumping worms negatively alter soil composition, depleting nutrients and disrupting acidity.

Gary Fish of the Maine Department of Agriculture confirmed the statewide presence of these invasive worms, marking a prolific year for their reproduction. As gardeners grapple with these challenges, they are discovering innovative ways to protect their gardens from this unsettling invasion.

Asian Jumping Worm

Jumping worms, known for their aggressive behavior when disturbed, are a source of concern for gardeners. Research is ongoing to manage them, with limited relief found through solarization-exposing worm-infested soil to 104 degrees Fahrenheit for at least three days under clear plastic.

Nevertheless, this approach has limitations because it works best in sealed bags or elevated beds rather than on the ground, where worms can escape the heat. Facing significant damage to her garden, including burrowed carrots and potatoes, Jessica Seiders realized action was necessary given the worms' prolific numbers.

Attempts at Eradication

Facing the absence of a foolproof method to eradicate jumping worms, Jessica Seiders is overhauling her gardening strategy this fall. She is eliminating weed mats, inadvertently creating an ideal breeding ground for the worms, and committing to avoiding their use in the future. At the Kennebec Estuary Land Trust in Bath, where jumping worms infest almost all garden beds, executive director Becky Kolak acknowledges the impossibility of eradication.

Instead, they are adjusting their gardening techniques to coexist with the worms.

The trust, responsible for 42 raised beds in an educational program, intends to implement solarization next spring based on advice from horticulturist Gary Fish, to lessen the worms' impact on their soil. Seiders plans to rely exclusively on raised beds and modify weed mat placement to gain better control over the soil in anticipation of spring. Elevated on blocks, the mats aim to minimize the worm's impact.

Due to worm-infested compost, Seiders chooses to purchase compost potentially free of worms. At the Kennebec Estuary Land Trust, where meticulous soil preparation is an annual ritual, jumping worms have disrupted these efforts.

Gary Fish expresses optimism for a decline in the worm population in 2023, drawing parallels with Vermont's experience. Possible factors for the decline include dry conditions or depletion of the worms' food source, though uncertainty persists. While gardeners await more effective eradication methods, Fish underscores the lack of viable management options for Asian jumping worms.