Asian Jumping Worms: The New Garden

Catherine Greenleaf - Lyme, NH

There’s a new menace in the garden and it is a real doozy. Amynthas agrestis, also known as the Asian Jumping worm, aggressively consumes the vital top layer of the soil on your property, damaging plants and trees and leaving behind a distorted soil composition that can render your garden sterile.

According to Professor Josef H. Gorres, a plant and soil scientist at the University of Vermont, Asian Jumping worms are also a danger to the health of New England forests since they permanently damage the soil food web. These worms eat the duff layer, the highly nutritious and spongey top three inches of soil that tree seedlings need to become established, bringing the growth of forests to a halt and preventing everything from insects and salamanders to turtles and birds from finding the food they need to survive.

Like so many invasives, this species hitchhiked in the soil of exotic plants shipped from Southeast Asia as far back as the 1890s. For several decades, millions of the worms were shipped to the U.S. and sold as fish bait. Over time, the species has managed to branch out across the country from nearly every major shipping port and their far reach into all six New England states has scientists greatly alarmed.

The adult worm averages eight inches in length. Its coloring is a greyish-brown and its smooth, milky-white reproductive collar, or clitellum, wraps all the way around the worm and is located close to its head. Compare this to your average European earthworm, which is reddish-brown in color, sports a raised clitellum that only encircles three-quarters of the worm’s girth, and is located half way down the body.

This worm exhibits a characteristic thrashing behavior when disturbed. It wiggles wildly when attempting to escape, which has earned it various nicknames, including crazy worm, disco worm and Alabama jumper.

ground hamburger. While the castings of your average earthworm are considered beneficial, the castings of this worm turn your property’s soil more acidic. Scientific testing shows higher levels of nitrogen, Fall 2022 phosphorous and ammonium nitrate, rendering the soil unfit for growth of plants or trees, according to Dr. Gale Ridge, chief entomologist at the Connecticut Agricultural Experiment Station.

The other problem? An Asian Jumping worm doesn’t need to find a mate since it reproduces parthogenically, and produces thousands of cocoons in a single season. While the adults die off once temperatures drop, the cocoons can survive through even our coldest winters in New England and have been shown to hang on for two full years before hatching.

What is most confounding to scientists is how fast they move. An Asian Jumping worm can cover the distance of a football field in a single growing season. The devastation of these worms is so extensive there are Facebook support groups for gardeners experiencing emotional distress after watching their beloved gardens destroyed.

Avoid buying bagged soil or mulch, since state authorities are now claiming that some commercially sold amendments are infested with Asian Jumping worms.

Buy only native plants. Native plants are already accustomed to the soil and climate in your region and don’t require amendments to survive.

Plant only bare-root plantings. Since bare-root plants are usually shipped without soil, you can avoid accidentally introducing the worms to your property.

Avoid buying plants from commercial nurseries. Garden centers can rarely guarantee that third-party growers and shippers are free of worm infestations. Give your business to native nurseries who go the extra mile to insure their soil is worm-free.

Also avoid buying plants from community plant sales or swapping plants with neighbors or friends.

The worms can enter your property from your neighbors’ yards. Be sure to regularly check the perimeters of your property and be sure to look under leaf litter.

If you think you already have Asian Jumping worms, there has been some success in using tea seed meal, a form of saponin that kills the worms. Follow instructions carefully and do not use near any water source. Scientists are saying that heating soil under plastic to 104 degrees for three consecutive days appears to kill the worms and the cocoons.

State officials are urging New England residents to keep a close eye on their properties and to report any sightings of Asian Jumping worms to their Cooperative Extension service.

Catherine Greenleaf is the director of St. Francis Wild Bird Center in Lyme, N.H. If you find an injured bird or turtle, please call (603) 795-4850.