WHO KNEW Yet Another Invasive Species Is Wreaking Havoc in Our Gardens and Woodlands?

It seems like more and more of my time in the garden is taken up combating invasives. This one is particularly destructive: the Asian jumping worm. Asian jumping worms resemble earthworms in appearance, except they have a distinct band, or clitellum, which completely encircles one end of their body.

If you don’t like snakes, you’re not going to like Asian jumping worms. These prolific pests (they reproduce through parthenogenesis—reproduction without mating) are aptly named because they wriggle and thrash like a snake when touched. They can reach up to 8 inches or more in length, and some move over the ground like a side-winding snake.

Nearly all earthworms in the Northeast are non-native, and they all change the soil structure and chemistry in our woodlands. The problem with Asian jumping worms is that they outcompete other worms by their sheer numbers and voraciousness. All earthworms eat tiny pieces of fallen leaves. These leaves, often referred to as “leaf litter”, form the topmost layer of the soil. Asian jumping worms quickly consume this top layer of leaf litter, depleting it of nutrients and rendering it unable to support other organisms (microbes, plants, and invertebrates).

You can tell if you have Asian jumping worms on your property by looking for their piles of excrement. These look like mounds of little dirt pellets. They’re particularly noticeable after a rainstorm. You’ll see them in your lawn, your garden, and in the woods. If you think you might have jumping worms, mix 1/3 cup of dry mustard to 1 gallon of water and pour it over the area where you think the worms might be. Within minutes, you’ll start to see the worms coming to the surface, because the mustard irritates them. Using gloves, be sure to pick up each worm you see and drop it into a pail with an inch or so of vinegar to kill the worms.

One method of killing Asian jumping worms is to apply Tea Seed Meal which is made from the seeds of the tea plant, Camellia. Tea Seed Meal is an organic fertilizer that is beneficial to the soil. It contains Saponin, which is deadly to the worms. However, it is important to note that Tea Seed Meal is also deadly to fish and mollusks, so it should not be used near bodies of water. Another potential method of killing jumping worms is by using biochar (charcoal-like substance produced by heating biomass in a low-oxygen environment), although this is still being studied.

What’s the bottom line? Be very careful introducing new plants, mulch, or soil into your garden, as most jumping worms spread to new areas by being transported unwittingly through these means. Test each new plant you buy by pouring the mustard/water mixture into the pot and removing and killing any worms which appear. Whenever you see a jumping worm in your garden, remove it and kill it. If you have a large infestation, consider using tea seed meal (as directed on the package), but be careful if you live near ponds, lakes, rivers, or streams.

There is a lot of information on Asian jumping worms online, if you want to learn more.