Jumping worms can grow up to eight inches long. When disturbed, they move like a snake, sometimes appearing to be jumping as their namesake would suggest. (Photo: Njh5880, Wikimedia Commons, CC BY-SA 4.0)
Jumping worms, native to Korea and Japan, are spreading quickly across several states within the U.S. The invasive worms degrade soil texture as they eat and deplete it of nutrients, causing problems for gardens and lawns. This week, Kara Holsopple of the Allegheny Front reports on how to spot and avoid jumping worms and what to do if you encounter them.
CURWOOD: It’s Living on Earth, I’m Steve Curwood.
BASCOMB: And I’m Bobby Bascomb
As people take care of lawns and gardens this spring they may encounter a new and unwelcome kind of worm. Jumping worms native to Japan and Korea are larger than earthworms and wriggle more like a snake. These invasive worms have been found across much of the eastern half of the United States and can be extremely damaging to soil quality. Kara Holsopple has been digging into the story for the Allegheny Front and has more.
HOLSOPPLE: It was about seven years ago when Nancy Canals first spotted them in Pittsburgh.
KNAUSS: I was working in my own yard, just digging up the ground and I thought- what are these things they don't look like your earthworms.
HOLSOPPLE: Canals is the Statewide Master Gardener Coordinator for Penn State Extension, so she knows her worms. These were large and they behaved more like snakes than common European earthworms.
KNAUSS: They ride around and jump and I'm thinking there's so many of them, these are different!
HOLSOPPLE: With a little research, she solved the mystery. They were Asian jumping worms and in a garden or forest habitat, they're a real problem canal says.
KNAUSS: The jumping worms actually degrade the soil. Your soil texture will change. So it's very granular, and people often compare it to coffee grounds.
HOLSOPPLE: She says the invasive species which lives close to the surface can eat anywhere from two to three times its body weight in soil every day. Those coffee grounds are the castings the worms excrete.
KNAUSS: What happens is if you get a rainstorm, the rain will hit those castings and you'll get a large flush of nutrients that will be available and the plants really can't absorb them all. So very little of those nutrients may reach some of the plants.
HOLSOPPLE: The nutrients just wash away and that can leave the soil depleted. Canal says researchers are looking at how the phenomenon could impact the germination of maple seedlings which rely on that upper layer of soil. In gardens, it presents other headaches.
KNAUSS: Personally I had a wild ginger just ground cover wild ginger growing in my garden, and it completely disappeared once I had the Asian jumping worms. So you now have bare soil and then that can leave space for your invasive plants like stoke grass, knotweed, garlic mustard to sort of take over.
HOLSOPPLE: Though not all plants are susceptible Knauss says the jumping worms can even live below turf grass, damaging the lawn so that it just lifts off. She says now is the time to prevent them in your yard. Because while the adults are annual and die off in the winter, their cocoons do not.
KNAUSS: These cocoons are very small, they're the size of a mustard seed. So while you are sharing plants with neighbors and you don't see any worms, there could be many, many cocoons in that soil.
HOLSOPPLE: In April when temperatures reached 50 degrees consistently. The cocoons hatch Knauss says if you're going to plant sales or trading with neighbors, the plants should be washed to remove garden soil.
KNAUSS: They can either be sold bare root, or they could be potted up in a sterile medium and then shared with somebody.
HOLSOPPLE: She says the cocoons are in mulch too. So buy it from a reputable dealer and make sure it's been heated to 130 degrees Fahrenheit. If prevention measures have failed, and you do end up having some of these in your yard or your garden, what can you do about them?
KNAUSS: One way that you can get rid of the cocoons is by solarization. So this is something that you do in late spring or early summer when our temperatures are high. You want to wet the area where you know you have the jumping worms and then cover it with clear polyethylene not black plastic, and let that heat up for two to three weeks until the soil temperature exceeds 104 degrees Fahrenheit for at least three days.
HOLSOPPLE: To get rid of the adults, you have to use your hands.
KNAUSS: I've done plenty of hand picking myself. You want to just put them in a plastic bag and set the bag in the sun and then throw it in the trash. You can also use a dry mustard solution. So making a solution of 1/3 cup of dry mustard in one gallon of water, and then you drench the area. And this mustard irritates the worms. It brings them to the surface so then you can easily harvest and pick them and throw them away.
HOLSOPPLE: What did you think when you saw the Asian worms in your garden?
KNAUSS: Actually, I was a little creeped out because I you know I'm not a fan of snakes. And then you know I learned more about it and unfortunately they're with me now.
HOLSOPPLE: You still have them?
KNAUSS: Yes, I do.
HOLSOPPLE: So the bottom line is if you can help it. Don't let Asian jumping worms happen to you or your garden.
BASCOMB: That story from reporter Kara Holsopple comes to us courtesy of the Allegheny Front.
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