I used to dig in my garden, unearth a worm and be delighted. I took it as a pat on the back for my hard work in making good soil that earthworms would want to be in doing their good work. But for the past year or so that delight has been gone. It has been replaced with dread. Dread that one of those worms would be unlike any other worm I'd encountered in my garden before.

A few years ago the first so-called jumping worms (aka Amynthas agrestis) were spotted in Wisconsin. They'd made their way here originally from Asia with stops in many northeastern and Midwest states and now at least Oregon in the Northwest. Call them crazy worms, Alabama jumpers, Jersey wigglers, snake worms or some variation of those, but I'll tell you what I call them: Bad news.

Wisconsin DNR graphic

These worms, which hang out on the upper layers of soil, are massive digesters of soil. This is not a good thing. What they leave behind is loose soil resembling coffee grounds and largely devoid of nutrients. Give them a little time and they destroy the composition of the soil to the point where plants are no longer anchored.

They reproduce without mating, laying impossible-to-find cocoons in the soil that overwinter even in cold areas, and oh, by the way, they mature so quickly that two generations can be produced in one season. They do their damage quickly.

Earlier this year, Jeff Epping, director of horticulture at Madison, Wisconsin's Olbrich Botanical Garden, where the worms were found a couple years ago, reported that a 5-year-old stand of Arborvitaes in the garden were all leaning to the east after a strong storm with west winds. These trees, which should have been well rooted, appeared to have been rocked because they aren't properly anchored in the loose soil. And Epping has dealt with them in his own garden. In May he reported on the damage he's noticed.

"I am also living with them in my home garden and have noticed very significant changes in my soil in parts of my garden," he wrote. "My soil structure has changed from typical silt loam soil to a granular, almost sandlike loose structure. The granules are so loose that I can easily scoop my hand into the top 3 to 5 inches of soil with minimal effort. The soil granules also seem to be a bit hydrophobic and certainly not moisture retentive. During periods of drought in the summer the plants in the worst jumping worm areas suffer from lack of moisture, way more than the areas where the worms are less concentrated."

In other words, no way in hell do I want these things in my garden. The odds, however, are not my favor. In fact, it's probably more of a matter of delaying the inevitable, because the worms are close. I knew they had been found in our county, but last week as I was working in a garden maintained by our master gardener group, I found a very suspicious worm. My master gardener training suggests that what I should have done was carefully collect the worm, study it to see if it matched the description of a jumping worm, photograph it, then put it in a Ziploc bag for further identification if needed and to solarize it before disposal (yeah, that means what you think it means: Cook it in a plastic bag in the sun). Instead what I did was scream, jump around, flip it onto the sidewalk, poke it to see how it moved, take a couple videos of it, squish it and throw it in the busy street. Because I'll be honest, I'm grossed out and I'm freaked out.

I'm waiting for positive confirmation from the DNR, but I have no doubt it's a jumping worm. When I went back later I found the distinctive coffee-ground soil and four more worms without looking hard. With my wits about me (and, um, another gardener with gloves) we bagged these.

Sidenote: Literally in the middle of writing this I received a call from my sister-in-law, who lives a couple miles from the garden I was working in and about 10 miles from my house, that she found several jumping worms.

Here's a really gross video from the Milwaukee Journal Sentinel:

Right now, my focus is on crossing my fingers that I can keep them out of my garden a bit longer and that means that I'm taking a lot of precautions.

Here's what I'm doing:

  1. No more passalong plants (probably). This is sad because this is how I get a lot of plants from family and friends. If I have to get a plant from someone I will root wash it at its garden of origin and then either pot it up in potting mix or take it home and immediately plant it. 
  2. No more plant sales. A lot of plant sales in the area were cancelled last year in order to slow the spread of jumping worms. They don't hatch until about mid-June here, which is after many sales happen, so it would not be difficult to take some eggs home in a pot with a new plant.
  3. Practicing OCD levels of garden cleanliness. When I work at the garden where I believe I spotted the worms I scrub all my tools, removing every speck of dirty. Same for my shoes and I have a pair of gloves I will only use there. All material collected there (weeds, deadheaded flowers, other detritus) is bagged for disposal. This as far as the DNR instructions go, but I'm taking the extra step of sterilizing everything with Lysol as well. I told you: OCD.
  4. I won't bring any commercial mulch onto my property. I'll still use so-called arborist chips from  trees we cut down here, but that's it. It is believed that the worms cannot withstand extreme heat, meaning that most commercial mulch should be OK, but it is believed they are still being transported this way (and I suspect that's how we got them at the garden downtown).
Jumping worms are shiny, even iridescent, and have a white or light collar that is flush with their body. In other words, really gross.

So what do you need to be on the lookout for if you live in an area where jumping worms have been found? Here's how you can identify them:
  • Look for the grainy, coffee-ground like soil at the surface. 
  • The worms will be in the top layer of soil just hanging out waiting to ruin some gardener's day. 
  • When you disturb one, they will behave unlike other worms, thrashing and writhing.
  • There will often be clusters of them.
  • They slither like snakes.
  • (This one is perhaps the most horrifying.) Sometimes when you pick one up their tails will break off and keep wriggling in your hand. You will know if this happens to me if I disappear for several days, having passed out and probably gotten a head injury.
  • They are shiny and almost iridescent. 
  • The band around them (called the clitellum) is white or light and smooth, whereas it is raised on other worms. It also encircles the body of a jumping worm where it is incomplete on other worms.
What to do if you find them:
  • Collect them for positive identification in a sealable plastic bag. Take a picture if need be, then repot them to your state DNR or extension master gardener service.When you're done with the worms, put the bag in the sun to kill the worms, then throw it away intact.
  • Repeat this as you find more. Anything you can do to slow the spread is important.
  • Be vigilant about cleaning your tools, even among areas in your garden if possible. 
  • Don't share plants from your garden. If you must, root wash them and remove all soil before repotting them or passing them on.
  • Try not to scream and freak out like a certain blogger may have.
Invasive species (both flora and fauna) happen, unfortunately. Rarely do we want to deal with them, but they are a fact of life. This one is particularly scary because it can do such serious damage (which goes well beyond the impact on gardeners; it could be catastrophic for agriculture) and as of now, there's no real method of control. 

I'll do my best to delay their arrival in my garden, look suspiciously upon every worm I encounter and yes, I'll probably scream, swear and generally freak out when the day comes that I find them. Some days that's just how it goes in the garden.

More information on jumping worms:


  1. So far none have been reported in Indiana. It is a scary thing to happen. How awful to have them come into your garden and destroy the soil. I would be freaking too.

  2. I keep wondering if they are in ag soil, farms etc. All of this worm reading also taught me that earthworms are not native. I've been leaving ziplock lunch bags with up to a dozen or more worms in the sun to fry. Then I double bag them and toss them in the garbage. They stink at that point. I feel virtuous but like I am barely treading water.

  3. Thanks for your advice on what to do if we do discover jumping worms. So much of the literature seems to focus on ID, without much advice on what to do if we are u fortunate enough to find them. Outagamie Co (WI). Master Gardeners have chosen to continue their annual plant sales with increased offerings of plugs from Walters potted in sterile potting soil, vegetables grown from seed in hothouses, and garden rummage (we gardeners tend to collect an amazing amount of it). We do allow gardeners to donate plants they have dug from their own gardens, only if they have tested the soil with a solution of/4 c dry mustard/gallon water, which evidently brings them squirming to the surface of the soil. I am working up the nerve to attempt this, dreading the possibility of them making an appearance in my gardens.
    We are currently facing formidable challenges grappling with some aggressive invasive in Wi, as we also focus on treating our ash trees with the recommended Bayer insecticide in the blue jug in hopes the Emerale Ash Borer will pass our trees by.

  4. Gross... but very helpful information. Happy to read Lisa Greenbow's comment that none have been reported in Indiana...yet.

  5. Thanks for the info, Erin. I haven't even heard about them. Hopefully they won't like our sandy soil in northern NE. Ugh. Good luck keeping them out of your gardens.

  6. Very interested to read this post. I definitely have them here in Philadelphia, although no one seems upset about it that I can tell. Years ago someone mentioned to me that there were bad worms, but I didn't know any more. I actually thought they were the good ones, and the fatter uglier ones were the bad ones. So I have been saving them when I find them outside the soil. No more. This is war. I noticed their coffee-ground soil particularly in one area, so I am going to try the dry mustard to see if I can get them out. Ugh!!


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