coping with invasive jumping worms, with brad herrick of uw-madison

THE QUESTION “What do I do about the Asian jumping worms that are destroying my soil?” has outpaced what was the most common thing I was asked, year in and year out, for decades as a garden writer—the relatively simple challenge of “How do I prune my hydrangea?”

Now gardeners from an ever-widening area of the country are voicing this far more troubling worry about an invasive species that seems to be on a mission of Manifest Destiny. They are present in about 38 states and several Canadian provinces.

Today’s guest, ecologist Brad Herrick from the University of Wisconsin-Madison Arboretum, has been studying jumping worms for a decade and is here to share the latest insights. Brad is the ecologist and research program manager at the UW-Madison Arboretum, where the staff first noticed the destructive handiwork of Asian jumping worms in 2013.

He explained what tactics and products have been explored by researchers to try to limit the spread, and whether we should keep mulching and improving our soil as we always have despite their presence, and more.

Read along as you listen to the Sept. 11, 2023 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on Apple Podcasts (iTunes) or Spotify or Stitcher (and browse my archive of podcasts here).

coping with jumping worms, with brad herrick


Margaret Roach: I’m always glad to talk to you. Sort of. Welcome back, Brad. I wish we could talk about happier topics someday together [laughter].

Brad Herrick: I know. Someday we will.

Margaret: I know. Can we talk about a plant or something someday? Oh, my goodness. Remember when we were just gardeners, not warriors, right?

And I learned about the worms, from—I think it was called Great Lakes Worm Watch organization—I learned online about the jumping worms in around 2013, and I contacted you. I don’t even remember how the trail led there.

I think we first talked in around January 2018, and we’ve discussed these invasive pests a few times before on the show and so forth. But just so that if people don’t know about them, just the really brief version of what are they, what’s the main problem that we’re talking about?

Brad: Yeah, so jumping worms, or snake worms as they’re commonly referred to, are kind of a new group of segmented earthworms that have made their way over to North America from parts of Asia, primarily Japan and the Korean Peninsula and parts of China. And they’re spreading quite quickly and over wide ranges. So they’re found right now in about 38 states …

Margaret: Oof!

Brad: …and several Canadian provinces.

And the main concern is that they consume organic matter, which a lot of organisms do, all earthworms do, but they do so in a way that really depletes the organic matter quickly. And so whether it’s a forest or your garden, they consume it very rapidly.

And then through that process, they really change the soil structure and the nutrient and carbon content of those soils. And those are impacts that have cascading effects to our plant health, to other organisms that live in the soil, to carbon that might have been in the soil that now is released into the atmosphere just through their burrowing activities and soil mixing.

And it is also important to note that where we’re seeing some of the biggest changes, especially in forests, are in areas that never had native earthworms to begin with. So areas that were in the last glaciation, those glaciers exterminated any native earthworms. So this is the last 10,000 years or so. And so forests, for example, in the Upper Midwest and New England are evolved without the presence of earthworms. And so these are novel critters coming in, and really fundamentally changing the ecosystem.

Margaret: Yes. Forest, you say, and that’s a place where leaf litter [laughter] is right?

Brad: Exactly.

Margaret: It’s the recycling, the natural slow recycling, and all the detritivore organisms, the helper creatures that do that, turning the organic material that falls down back into feeding the soil and the cycle repeats itself. And it’s the basis of all of our, really, of the environment.

So the soil layer is destroyed. And the thing is that when you have these worms, as you just said, they do such a quick job of processing the soil and they turn it to what looks like sort of a cross between coffee grounds and hamburger meat. It doesn’t have the same tilth as it used to have, and it almost feels like the plants are loose in the soil, things aren’t holding.

And I think in the past, you’ve told me that in places like the forests of the Great Lakes and in the Smoky Mountain areas where they are been present a long time, that the saplings can’t even get a root hold in because the soil is disturbed in areas where they’re very concentrated, or something like that.

Brad: That’s right.

Margaret: That sound about right?

Brad: That’s right, yeah. So you have, for example, sugar maple seedlings, any kind of seedlings really, woody species, have a hard time getting established in that upper layer of the soil, which is exactly the area that those jumping worms are continuously turning over, incorporating nutrients and making, which you think might be a good thing, incorporating nutrients. But what they’re doing is they change the soil, like you suggest into this coffee ground-like, really porous soil, and there’s just nothing for the roots to hold onto. And what we find often is that soil, it’s so erodable because there’s nothing holding it in place. It just gets sucked away. And you’re almost left with just mineral soil, which is very inhospitable for a lot of them.

Margaret: So I had a reader write to me last week actually, and it was a very emotional note, she honestly said, “I want to sell my house. I want to get away from what I’m seeing.” And very, again, very sincerely said, “How are you coping?” She said, “It’s very emotional and it’s terrifying.”

And how do people cope with watching this decimation and feeling powerless? That increasing number, you said 38 states, the last time we spoke a couple of years ago was fewer than that. And I remember when they first came to your, you noted them on the campus, they moved acres within a short period of time. Correct? They spread exponentially.

So it’s heartbreaking. It’s terrifying. And I know there’s research going on in a lot of different places, but what are you guys, you’re a decade in, what are you doing; are you doing anything? Are you going around picking up worms and destroying them? What are you doing? I know there’s different materials that are being suggested to apply and so on and so forth. What are you doing?

Brad: Good question. It really depends, in terms of control or management of these critters, it really depends on specific and local sort of situation. So whether you’re talking about a forest, or someone’s urban garden, or maybe a larger organic garden, it really depends on the situation.

For us at the arboretum here, where we’re talking about acres and acres of sugar maple-basswood forest being invaded, we’re not talking about control anymore. That’s not a feasible thing, and we have to accept that. And what’s interesting is we don’t really see, just walking through the forest, a change in the vegetation.

Now, I have seven years of data that I’m hopefully analyzing this fall, which may sort of pop out some effects specifically in terms of what’s happening at the sapling-seedling layer.

But the plants are just one part of the ecosystem. And what happens with earthworms, I think, is that their impact can often be less obvious in the short term than something like spongy moth or Emerald Ash Borer, because they’re really changing nutrient cycling and affecting the microbial community and the fungi relationships, all these things that eventually will impact a lot of different things.

It’s hard to kind of talk about the impacts because while we see some impacts in certain situations, it may be that it’s a longer-term situation where we’ll see impacts later on.

Now that’s in our specific urban sugar maple forests. In gardens, where we’ve done some work as well with folks, we’re seeing much more of an impact more quickly. But it does, again, depend on the situation. So it seems like for folks that have had jumping worms for four or five years, where at first it didn’t see much of an impact, now they’re seeing all sorts of impacts to even plants like hostas, which are the poster child of hardiness and ability to transplant them. And again, transplanting anything into a really porous soil medium, it’s not feasible. And I feel for the person.

Margaret: My reader, sure.

Brad: It’s very much an emotional response.

Margaret: And, again, research has gone in terms of… And we should say that these are annual creatures; the adults die in the winter, but they leave behind these cocoons of eggs that are so small, they’re almost invisible. So that’s how they perpetuate year to year. And that different scientists, researchers such as yourself, people have experimented with extremes of heat or cold to kill the cocoons, the overwintering cocoons or blah, blah, blah, other things.

To bring the worms to the surface, everything from mustard powder, and then collect all the worms and kill them in plastic bags in the sun to fertilizers, natural fertilizers that are not labeled for the purpose, like tea seed meal, I believe. And then sharp, sort of irritating to the skin of these animals. Soil amendments like diatomaceous earth and bio-char sort of ground-up charcoal, all these things that you read about.

But is there any thought that, again, in the garden setting, that any of this has any is worth doing? Because none of it’s cheap and none of it’s easy. So you said “we’re not talking about control anymore.” So anything to say about any of those?

Brad: We’re not thinking about control in some of the forests, but the gardens, it does depend on how invaded your garden is. You can still do a lot of good if you catch an invasion early. And so again, I always kind of harp on education, and understanding what these critters are, identifying changes in your yard. Because there are things, so there’s a couple of things that have been researched, relatively new.

One is a product that’s been on the market for a while called BotaniGard, and this is an entomopathogenic fungus, which is the fungus called Beauveria bassiana; it’s a naturally occurring fungus in the soil. And there’s a research paper out now that showed that this product as well, as just the fungus isolate itself, is pretty effective at killing the actual jumping worms.

It’s as like a granular application that you irrigate in, or you spray in. And the benefit of that is that it’s already labeled for this use. It’s been in the market for a while. It does affect all soft-bodied pest organisms; so there’s always that to know about. But that will work. That’s an approach with some science behind it.

And like you mentioned, we also know that heat works, and heat is probably the best solution we have right now. It addresses both the live earthworm and its cocoons, which you mentioned earlier.

Margaret: So we could solarize in spring into summer, we could solarize a raised bed, for instance, that we grow vegetables in; let it be fallow, but solarize it, something like that. But we can’t do that in a planted ornamental bed that’s densely planted. Do you know what I mean? We can’t solarize it. So where there are no plants, and agriculturally, the same thing would be true. Bare soil, I guess?

Brad: Exactly.

Margaret: Can be there for sure. Or if you want to take everything out of an area, you could do it. But what I find is that they—and I’m probably in the five-year mark as well—some years like last year was very dry here, and it was almost as if they had gone away. And this year, which has been very, very wet, it’s as if they’ve quintupled in a minute and they’re prospering.

So it’s not the same year to year, even in the same place. And the population explosion though, seems pretty impressive. They really move.

Brad: And that’s sort of what’s sort of disheartening, is we’re in our second year in the Midwest here of drought, and our numbers are way down.

Margaret: That’s exactly what happened here last year.

Brad: Exactly. Yeah. And then you mentioned you guys have had a lot of precipitation this year, and that just shows that what’s happening is those cocoons are forming a cocoon bank where they’re not going to hatch until the conditions are ideal. And so one year might look great, it’s like, “Oh, I’ve taken care of them. This drought took care of them.” And the next year, like you’re saying, you see a quintuple of earthworms coming out, just because those cocoons are able to rehydrate and hatch again.

So yeah, it’s really frustrating in that sense. And that’s the kind of thing that solarization or some other heat treatment that can get hotter than just the ambient air temperature, where it not only dries them out, but it actually kills them. Even folks are using things like torches, [laughter] or I’m thinking about how do you steam the soil sterilize?

Margaret: Well, people with greenhouses do that. If they get a fungal pathogen in a greenhouse, like my flower-farming friends nearby, they’re organic farmers; they can’t use most fungicides, so they have to rent a steamer. Yeah, exactly. But for our basic garden, so the BotaniGard is one possibility, but some of these other, either these sort of irritants or the tea seed meal or whatever, is that just going to bring them to the surface? Is that the idea of that as well? I don’t really know what it even does or if it has any efficacy or not?

Brad: So the tea seed meal, similarly with people who have been using a mixing of vinegar and water, or soap and water.

Margaret: I’ve seen mustard powder and water being recommended, too [laughter].

Brad: Yeah, mustard powder and water. So the mustard powder and water and the tea seed meal will bring them to the surface. Mustard powder will not kill them, but the tea seed meal will, as will the vinegar and water and the soap and water.

We don’t think that the tea seed meal impacts the plants at all, which is a good thing. Same with the mustard powder. But the vinegar and soap and water could very well, and that’s the other. There’s always a trade-off.

Margaret: Well, and it depends on where you apply it. So again, if it’s along your walkway and it’s among the cracks in the pavers, okay, you could probably do the vinegar, etc., but yeah.

Brad: You want to stay away from the plant root zone.

Margaret: Right. It’s a pretty gruesome experience also, I will say, the collecting of worm bodies [laughter]. It’s fragrant. It’s also extremely fragrant in summer. And the other thing is, and this is really crazy to think about, but I do think about it, is so, again, those adults are going to die anyway in the winter. They’re annual organisms. So at a certain point, those cocoons have already been laid, or whatever the word is.

So you could put lots of this stuff on and gather up all these hideous, smelly dead worms that are decaying and so forth. But they’ve left their mark, haven’t they? So I guess this would be a multi-year thing to do, until you diminished and diminished and diminished the adult population to the point where you didn’t have as many cocoons. It would be a multi-year… It wouldn’t be a one-and-done at all?

Brad: That’s right. That’s an important message, Margaret, that it’s not, and this is the case with any invasive species, frankly.

Margaret: I agree. Yes.

Brad: It’s hardly ever a one-and-done thing. It’s a multi-year process, and what you’re basically wanting to do is deplete that cocoon bank over a number of years. And I think that’s the way to look at it. And I could see that in theory being effective, depending on how large of a scale you’re working on. At some point, it just becomes too labor-intensive maybe. But yeah, I think that’s a good way to look at it.

There’s things that are really labor-intensive, like physical barriers. Driving in—there’s experiments that have experimented with jumping worms in forests by putting in metal flashing little quadrats to experiment with. They don’t want jumping worms going into these, testing the soil without them. And so putting that kind of physical barrier in down to six inches, so they’re not—these are only surface-dwelling earthworms, and they’re not usually going to go very deep. And so if you’re like, “My neighbor has them, I don’t want them,” you could spend some time and put some kind of physical barrier around your raised bed.

Margaret: A worm fence [laughter]!

Brad: A worm fence.

Margaret: Underground though.

Brad: It’s probably extreme, but it’s something that could be done.

Margaret: I want to make sure to talk about the other side of the equation of what to do in the powerlessness and the worry and so forth. And I’ve read different things about this. Do I add mulch at the times when I normally do? In other words, do I “feed them” more organic material, or do I just leave them there in their degraded soil? Or do I add more soil on top of where the soil has receded? What about that we have our usual methods of caring for our soil and garden beds, but what do you think about that? Feed them, don’t feed them?

Brad: That is the question. I would say mulch is a food for these critters, but really at the end of the day, we want to be able to enjoy our gardens. We want to garden, and by enjoying our gardens, we want to make sure that the plants are as healthy as they can be. And mulch is a really important part of that.

Margaret: Yes. Serves other purposes, yes.

Brad: Absolutely. And one thing to try is experimenting with different types of mulch. So all mulch, all organic matter is not created equal. So leaf mulch has a very low, depending on the type of leaves, has a lower carbon-to-nitrogen ratio than something like grass mulch or hay mulch. So the leaves break down faster, and the earthworms are able to consume it more readily. Whereas native grass mulch or hay or straw mulch, even pine mulch, pine needles, aren’t going to break down as fast and aren’t as palatable to jumping worms or any earthworms.

And so trying some different types of mulch, I think, is a good first step to see, “Hey, maybe I found something that sticks around for a while,” and the earthworm don’t do as well.

Otherwise, that’s one option. The other option is just stick with, if you already have them, stick with your mulch system that will… at least maybe the benefit of the mulch will outweigh the negative part of the earthworms, and those plants will still be able to do O.K. and persist. So it’s like too much of a good thing will overcome a negative thing.

Margaret: That’s the direction I’ve gone, because I can’t watch the… You may have a beautiful established tree and suddenly it’s got surface roots because the soil’s receded. Do you know what I mean? I’m like, well, not that I’m going to bury the tree and suffocate it. I don’t mean that, but I want to keep it at the level it was at.

Brad: One thing that I’ve just started thinking a little bit about is as we learn more about which plants, which plant families, which plant traits, are more susceptible to jumping worms, we might think about where these jumping worms come from, which are parts of Asia, and are there ornamentals from that part of the world that might be just fine coexisting with jumping worms, and that maybe we think about shifting some of our garden targets to plants that do just fine in the presence of all sorts of disturbances [laughter], and maybe not the ones that we traditionally wanted to garden, but maybe there’s an opportunity for some new gardening ideas and practices.

At some point, we have to probably accept some level of this jumping-worm pressure, at least in some of our gardens, and see how we can adapt to that, which is not always what people want to hear.

Margaret: No, but it’s realistic, because again, the first few years we were talking more about like, “O.K., don’t spread them. Don’t share plants, don’t do this, don’t do that.” But in my region, in New England, I’m hearing from people everywhere who have them. It’s super-widespread. And similarly, I think, in the area adjacent to where you are, there’s a lot of…

Well, Brad Herrick from University of Wisconsin-Madison Arboretum, like I said, I want you to tell me, you should email me and tell me what your favorite plant is, and we’ll do an episode on that, instead of talking about these damn worms all the time [laughter].

Brad: Sounds like a deal.

Margaret: O.K. And thank you so much for making time. I know you’re swamped, and thank you so much.


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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 14th year in March 2023. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the Sept. 11, 2023 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify or Stitcher (and browse my archive of podcasts here).

  1. mary brighthaupt says:

    Very timely for me. I have words of hope for those with smaller gardens. I moved into a new garden last year in zone 5b and brought in much shredded wood mulch and compost. This summer I noticed the worms. Lord have mercy! The horror of pulling out a struggling shrub and seeing the bottom of hole filled with these worms! I had to lie down in a dark room for a few days, but put on my big girl pants and went to battle. I got a bucket, gloves and cultivator. Most evenings, after a cocktail, I go wormin’! I moisten the area to lure them and rake along the surface. I dump into a bucket then dispose in a special trash can. After about a month of this new hobby, I do see progress. I’ve learned to scrape up against root balls, a favorite hiding spot. My advice: don’t look at them, wear thick gloves so you don’t feel them, and be prepared for the really big ones that look like snakes. I’ve ordered tea seed meal and will sprinkle that around plants to help defend roots. That’s my method of coping.

      1. margaret says:

        Just do a Google search for tea seed meal and see if suppliers who serve your region come up. There are a couple of companies making this fertilizer now.

        1. Charlotte says:

          My chickens eat them. I expose them when I’m digging and they get gobbled up quite voraciously. Thank you for the control suggestions. I will definitely try them

          1. margaret says:

            I keep reading the advice on various cooperative extension websites not to eat the meat or eggs from poultry that are feasting on jumping worms. Don’t know what research it is based on. Click on “bioaccumulation of heavy metals” subheading on this page on UMass-Amherst website.

    1. Allyson Levy says:

      Thanks for this episode. This is one of the top 2 questions we get asked ALL the time when people visit the arboretum.-what to do about jumping worms and how do we deal with it in a 21 acre garden.
      We see how stressed out, concerned and confused about the different tactics, and quite frankly the limited information about how to deal with these pests.
      I really appreciated Brad’s comment about “shifting some of our garden targets to plants that do just fine in the presence of all sorts of disturbances and maybe not the ones that we traditionally wanted to garden, but maybe there’s an opportunity for some new gardening ideas and practices.”. YES!!

      My advice straight up is take a breathe, and don’t let this pest get you out of gardening. I’ve heard people say they can’t keep us with the killing of them and it’s taking the fun out of gardening. I recommend acknowledging you them (if that is the case) and do the things you CAN do to limit their spread (sharing plants that are bare-rooted or solarizing if you have a small garden . AND to keep adding soil, woodchips or what ever amendment that the particular plant calls for as a mulch if you see it depleted in areas. So what if you’re feeding the worms- more importantly you are feeding your plants, and these types of additives are much much cheaper that chemical/organic applications of whatever that is currently being recommended for killing the worms. Especially because we really don’t know what these other “solutions” can do over a 50 or 10 or even 5 year period to other living organisms in the soil, (many which are not bad).
      I say save your money on these products and use it to buy more “woody” plants to restore the carbon, add beauty, and more importantly diversity to your garden. As Brad said, “adapt to that, which is not always what people want to hear- or find plants that co-evolve with these worms in parts of Asia, and are there ornamentals and edible (my addition) plants from that part of the world that might be just fine coexisting with jumping worms, and that maybe we think about shifting some of our garden targets to plants that do just fine in the presence of all sorts of disturbances.”
      As always thanks for another great podcast.

  2. Daniel S says:

    Thanks, Margaret, for this episode. My sense is that, while these alone are not up to the challenge, the old “best practices” remain important because there are many places that do not host jumping worms yet, even if they exist in the broader region. If you know or suspect these worms are present where you garden, share seeds or cuttings, not rooted plants. Don’t move rooted plants from an impacted part of the garden to a yet-unimpacted periphery without first removing all soil. If you don’t have jumping worms, be very careful about bringing in rooted plants from unprofessional sources and only buy unbagged mulches/soils from businesses with high standards. These practices can be a pain but prevention is always the best course of action with invasive species.

  3. mary says:

    Can someone help me to downsize the BotaniGard application instructions to 2 gallons of water: ½ to 2 pounds of BotaniGard 22WP per 100 gallons water.

    1. CrewMom says:

      Hi Mary, since you want to make 2 gallons of solution, or 1/50th of the 100 gallons the directions describe, you want to use 1/50th of the amount of BotaniGard. So that would be 1/50th of 11/2 to 2 pounds of BotaniGard, or .48-.64 ounces of BotaniGard to 2 gallons of water. Hope that helps.

      1. mary says:

        Thanks CM :). Its something like $95 before shipping so I want to make sure I create an effective dose. I tried the mustard slurry. It wasnt any more effective than just watering, in my garden at least. GLTA!

  4. Michelle Champoux says:

    I have just discovered my infestation although I may have missed early signs. (I’m in Central Vermont.) I have been working on the assumption that fewer adults, over time, will result in fewer cocoons and therefore an eventual reduction of the population. But I wonder if researchers have determined the worms’ life cycle clearly enough to know when newly emerged snake worms lay eggs? In other words is there an optimal time (as in battles with invasive plants) to seek out and destroy?

    1. margaret says:

      In the north they need about 90 frost-free days to go from hatchling to adult and to begin to produce cocoons, so it is often stated by researchers that cocoons are produced starting in August sometime. I don’t think year to year you can know what the precise date is, but that’s the general explanation.

      1. Michelle Champoux says:

        Thank you! So maybe starting to look/find/destroy before, say, mid August will be most effective…as soon as the newly hatched are big enough to find. Then off worm duty until next year. Or -dreadful thought- do they keep producing cocoons til they freeze?

        1. Lynn says:

          I start right away in the spring, my thought being the smaller they are, the easier they are to get rid of. I do about 30 minutes a day, especially after it has rained. My other strategy is to put leaves in black garbage bags or paper leaf bags, and leave the bags as “traps” in a few spots in my garden. If it is either sunny or rainy, they seem to hide under the garbage bags for cover. It makes it easier to find them, since they seem to collect under the bags. It’s worth a try! I will have to also try the cocktail suggestion above!

          1. margaret says:

            It’s not recommended to feed the jumping worms to chickens/ducks etc. says UMass-Amherst and other sources if the eggs or meat of the poultry is to be eaten. (Look under “bioaccumulation of heavy metals on their FAQ page.)

  5. Tins says:

    I found them in my compost pile last year. I hand pick them out with much squealing and swearing. I solarized it. I still have some this year. I pull the worms out before I use the compost. So far none in rest of garden. I’m so paranoid I know I’ve killed some innocent worms.
    A friend told me her ducks love them. They are too big for her chickens.

    1. Beckie K says:

      Note for your friend re: feeding the worms to chickens from UMass Amherst Extension. I would assume this applies to ducks as well.

      Is it true that jumping worms bioaccumulate toxins from the soil and therefore are not good to feed to chickens?
      In terms of bioaccumulation, jumping worms can be harmful if your soil has elevated concentrations of metals (e.g., lead, mercury, arsenic) or even organic compounds (e.g., banned pesticides like DDT, polychlorinated biphenyls). Low levels of metals, metalloids, and other contaminants in the soil ensures low transfer to chickens and other ground foraging birds. In general, it is not recommended to feed jumping worm species to chickens, especially if the eggs or meat from those birds is to be consumed.

  6. Julie says:

    Hi thanks for the info on this important topic. Two questions…is it ok to turn under the JW affected top layer into the deeper soil layer by turning over the soil and bringing unaffected soil back up, or is incorporating it deeper a bad idea? Also, what about scraping up some of that top layer and adding it into a hot compost bin to try to kill off some of the eggs- possibly early in the spring when they might not have hatched or are smaller and maybe more vulnerable?

  7. Jan says:

    Thank you, very informative! New question: Now that I have them…and can potentially kill them, how do I get my soil back to something my plants can use – since their castings seem to repel water?

    After a rain, or every now and then, I’ve gone around my yard “stomping” around newly planted perennials and shrubs- they seem to like potting soil better than the soil in my yard, which is counterintuitive – purposely compressing the soil on the roots. I did seem to notice that they didn’t seem to be as big of a problem in the nursery plants with a coco coir vs. compost “base” (i.e from Monrovia Nurseries). The tea seed meal seems to work, but gosh do they stink!!!! (also if you put them in a bag in the garbage, make sure it is tied tight and nothing pokes a hole in it!)

    A more important concern is that the worms will loosen the soil around huge old oaks and other shallow rooted trees in the woods enough that their roots won’t have support in strong winds and they will fall on my house!

    Also, one potential problem about a “fence”, is that they climb – found them in pots by my front door that is 4 steps up from the ground.

  8. Sharon says:

    First time I read your blog outside on my phone, while on break from moving perennials, and I found two of these invasive worms. Ugh. Much longer than I have seen in the past. It has been a while. First time I let the research scientist at my state (Vermont) know. Talk about timing Margaret.

    1. margaret says:

      At this time of year (August-September) the first generation of this years adults are at their largest size. And some a VERY large!

    2. dona abramson says:

      We’ve had them( or noticed them ) about 4 years. I culllike crazy in the spring when I first see them to try and get them before they reproduce. First summer I was totally obsessed with them like a mad woman- filling up a 5 gallon bucket( with natural soapy and water) . My husband solarizes them on the driveway. Yuck. But even more icky is the bucket of decomposed worm sludge .. Dare I ask if it could go into the compost or is there a chance some cocoons could still be viable in the water/ sludge bucket( there are worms in the compost bin too…)?
      Margaret- any thoughts on what to do with the worm slugs?
      THANK YOU from Saugerties

      1. margaret says:

        I don’t know a firm answer except they are dead adults, so I dump the bucket along the edge of the road or some other out of the way spot where I won’t smell it (since they smell so bad!). I don’t put soap in my compost heap because in the same way it harmed the worms it will harm other soft-bodies beneficial organisms living in there, no?

  9. Katherine says:

    A columbine bed mulched with a very thin layer of tiny (corn kernal size) pebbles banished worms from that place in one year. Elsewhere, we just keep mulching, mulching, mulching. But we have the time. I, too, go wormin’, bucket and gloves always by the door. Numbers are way down from 3 years ago and the surrounding wild vegetation looks fine so far.

  10. Joy VanderLek says:

    This article really is timely-yes, we now have them at our Pollinator Pathway gardens. The info is good, but I wonder if there is harm to other soil organism and critters these treatments (both to bring them to the surface and to kill the worms and/or eggs).

    1. margaret says:

      Yes, Joy, any treatment even if organic (which these are), will similarly affect other soft-bodies soil-dwelling organisms, not just the target organism. Even when people “weed” with homemade soap and water and vinegar concoctions I hear about — those, too, affect any organism in the soil. So that is another part of the decision=making process.

    2. margaret says:

      Any soft-bodied soil-dweller would be affected by any “treatment” you try on the worms, too — from solarizing to using soap/vinegar and these products Brad mentioned.

  11. judi says:

    What about gravel gardens; i.e. 6 inches or so of gravel on top of the soil. Will that work to keep the jumping worms out of the gravel garden area since they live in the top part of the soil?

    1. cricket beauregard-lewis says:

      Gravel sound like a good idea. What about Buckwheat hulls for mulching…not cheap but maybe hard to breakdown?

  12. Cynthia says:

    From UMass:
    What is the status of using tea seed meal for controlling jumping worms?
    Tea seed meal is labeled for use as a lawn fertilizer only and is not legally approved for any other use. It contains naturally occurring saponins (chemicals with soap-like properties), which have been found to kill earthworms. However, it is not a certified vermicide and its effects on other organisms, particularly mollusks and fish (if it gets washed into waterways), can be severe.

  13. Helen coukos says:

    So upset about these worms. I love making and using leaf mulch and they say to leave your leaves so how does this affect that? I noticed all my leaf much i used in all my gardens to be gone. My vegetable garden was horrible, been finding lots of worms, very depressed. They say it’s affecting native plants which is also very depressing.

  14. Geraldine says:

    Thanks so much for keeping us informed of these worms. It was because of your original podcast on them that we realized we had them. We are living with them. The garden bed where we first discovered them is a shady spring garden (no bulbs). It has done fine over these years. This has made me wonder if the growing habits of plants influence the impact these worms have.
    These worms are present in a section of the garden where we’ve been battling knotweed for 40 years. I was hoping they would weaken the knotweed. Alas, it does not appear to be the case.

  15. Sarina V. says:

    I have dealt with a lot of these worms in my garden over the past three years. I don’t remember where I read this tip about disposal, but it’s a good one. Fill the bottom of a 5-gallon bucket with a few inches of rabbit food. Take the bucket with you every time you are weeding or planting (disturbing the soil and therefore bringing the worms to the surface). Toss the worms in the bucket. Occasionally shake the bucket to cover the worms with rabbit food. This kills the worms but diminishes the stench. The worms dry out, and you can dump the whole hellish mixture in a trash bag to dispose. This method allows me to dispose of far more worms than I did with other methods (buckets of water, tossing onto the driveway, stomping, chopping). As the growing season progresses, I see less and less worms. I also take care to promptly remove dead foliage right away.

  16. Cindy Hirsch says:

    Thank you for the above information…..I’m the only home in my area with a large invasion of these pesky worms! No place I go has any information!!! I have a question. If I rake the mulch out of a large empty space and put a thick layer of topsoil, then seed it…..what do you think will happen to all the cocoons ?
    Also, where can I purchase botani guard? Thank you,
    Cindy from Michigan

  17. Cathy says:

    It’s time to apply mulch to my beds, but I’m concerned about bringing these worm cocoons onto my property in the mulch (and losing sleep over it). I just got a yard of mulch, and had it dumped onto clear plastic sheeting, I spread it out to about 8 inches thick and wrapped it in clear plastic nice and tight. I’m hoping that it will get to 104 degrees for three days to kill the stinking things if they are in there. Today it was about 70 degrees here in Rhinebeck, NY. I checked the temp in the mulch and it was over 104 degrees. I got blasted by the heat when I pulled the plastic back.

  18. Kristina Pavlovic says:

    I live in Maryland and have an abundance of snakeworms throughout much of my property. I am going to try Botanigard but I am unsure how best to apply it. I purchased the wettable powder and plan to mix it in a 2 gal. sprayer. I’m not sure how much powder to add to the water. Also, does it need to be irrigated in after applying and how often should I apply it?
    Any information you can provide would be greatly appreciated.
    Kris Pavlovic

  19. Joni Boulware says:

    I have started a campaign against these nasty worms. Tea seed meal is really the only solution. In addition, I have decided to abandon composting because I find that I am just breeding the worms and if I dont’ use the compost quickly enough they literally turn it to sludge – pure castings that clump together and ultimately are unusable. Worms in the lawn were really thick near my compost bins. I may go to an elevated bin I can turn and use only material from the kitchen or garden clippings that have not been on the ground.

    I am quite sure cocoons were brought in with mulch that was generously applied all around the garden and other beds. They might also have already been on the property and then were raked up with fallen leaves used in the compost. Who knows?

    For the lawn I wait until a big rain storm is predicted and then apply it with a spreader like granular fertilizer. That has knocked out the population quite a bit. For the garden or select areas, I have started using a liquified version. I put 1/2 c. tea seed meal in a five gallon bucket and fill with water. I take that liquid and dilute it by half into a sprinkler can and use in the garden. Because the tea seed meal takes a while to dissolve and never completely, you can keep adding water to the 5 gallon bucket and diluting again into the watering can. I probably get 15 gallons of effective liquid from one half cup of tea seed meal. It takes effort, but it is very satisfying to see those worms be done with.
    I have tried solarizing my compost. I have left clear bags of screened compost in the hot Texas sun for a week or even longer and it still does not kill all the cocoons. But it kills all the worms and probably some of the cocoons. Then when the compost goes into the raised beds, as soon as I detect any baby worms, I give the bed the tea seed meal treatment. It is shocking the number of tiny baby worms that have clearly just hatched from cocoons I thought should have been killed by solarization. I feel like if I stay on top of the worms when they are too tiny to create cocoons, eventually I will win!
    I am also going to quit buying plants from nurseries for my vegetable garden. All seedlings by me from now on.
    I give tea seed meal the total thumbs up. It does not bother me at all that some “good” worms may be killed as well. From what I can tell, once the jumping worms move into an area, the other worms don’t survive or leave. I used to try to figure out which worms were which. It is impossible when the worms are young. So all bad in my book now.

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