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Attack of the killer worms?

Madison, IL(Zone 6b)

I'm not sure where to ask this question, so I'm starting here on this forum since the linked article says that night crawlers are good for the vegie garden and flowers, but bad for trees and shrubs; especially woodlands and forest. Has anybody ever heard of this? I couldn't find any previous threads on this topic. My yard is loaded with night crawlers and I'm getting ready to plant several shade loving shrubs. I've been putting down woodchips on the shady path where I plan to plant azaleas and hydrangeas. This article has "opened a can of worms" as I always thought the more worms the better.

Kalispell, MT(Zone 4b)

You have to quit believing what you read. That article is so full I can't believe it. Any conversion of carbon matter to a nitrogenous waste of worm castings are what has made leaves and soil the ultimate regeneration of leaf matter into utilizable forests, understory, and native plants. Any situation that worms are too populace would result in loss of worms not plants. their trailings are the source of plant diversity and growth. I totally dissagree. steve.

Ouch, I'm going to have to concur with that article.

greenbrain has questioned whether earthworms were good. I suspect he/she has been reading they might not be good for all types of gardens. Earthworms are actually great for many gardens for the very reasons mentioned however they are not so great for forests or woodland gardens which is where they are escaping to from our gardens.

Here are some links to the flip side of the coin as pertains to the existence of some earthworms in our soil. This is merely another point of view to consider as there are mounting concerns out there associated with introduced earthworms. Here are some of the issues North American woodland gardeners may be facing-
Excerpt from National Geographic’s site-

Plants such as ferns "are rooted in the forest floor, [therefore] if the forest floor is disturbed or destroyed, it makes sense that some of the plants would decline," said Groffman, of the Institute of Ecosystem Studies. Declines in other plants, such as the northeastern trout lily (Erythonium), have also been anecdotally linked with exotic earthworm invasions, he said.
Earthworms cause basic changes in the structure, biology, and chemistry of soil, said Patrick J. Bohlen, a soil biologist at the MacArthur Agro-Ecology Research Center in Lake Placid, Florida. "Whether that is beneficial or not, depends on the location," he said.
Some exotic earthworms, such as L. rubellus, are examples of species that take advantage of human disturbance of the environment, said Paul F. Hendrix of the University of Georgia's Department of Crop and Soils Sciences, in Athens.

This following sums up the situation with earth worms. Excerpt from here-
There are 8 species of European earthworms invading forest in the northeastern U.S. Some of them, such as Dendrobaena octeadra, an epigeic species that lives in the duff, but does not eat the duff, have no negative impacts that we can see.

Several other species such as Apporectodea (3 species, known as angle worms), Octolasion tyrtaeum, and Dendrodrilus rubidus, are endogeic (they live in the soil), and they have some impact on the forest. They have lateral branching burrows.

Then there is the genus Lumbricus, with two species. L. rubellus (known as the leaf worm, and epi-endogeic species) which completely changes the forest floor, by eating the duff, thus changing the type of seedbed, and the species of plants that can germinate there in the future. It also kills the standing crop of tree seedlings, ferns and wildflowers, in some cases no seed source is left. The duff is consumed within a few days in any one spot. I often see exposed fine root systems of plants when this species is invading.

Finally there is L. terrestris, the night crawler, which is in the anecic functional group, meaning that it lives in vertical burrows, and eat fresh litter. They prevent the forest floor from being reestablished by eating all of the litter that falls each year.

All of the earthworms cement soil particles together, and replace a group of native insects that are more efficient at aerating the soil than the earthworms, so that the soil becomes hard and dry when the worms invade.

What this all amounts to is a re-engineering of the entire ecosystem. Less water infiltrates the soils, nutrients are less available, and the seedbed is different. Therefore, the forest type will change, or even be converted to savanna, as is happening to old growth hemlock in some parts of Sylvania.

A large scientific literature is developing on this forest decline syndrome as we have started to call it. The really unique thing about invasive species that are ecosystem engineers is that they know no ownership
boundaries, and can thus destroy remaining 'protected' old growth.

Any worm that I find in my woodlands is going to be European or Asian as there are no earthworms that are indigenous to my area. Keeps it simple for me as I don’t need to learn to identify which worms belong and which don’t because all are introduced. All worms I come across in my woodland gardens end up tossed on a plant ledge in a preform pond I have specifically installed for raccoons with the lowest level of the pond that is filled with a little bit of water being reserved for Rusty Crayfish which is another species that is not indigenous to my area. This helps me keep the raccoons out of other areas on my property by providing them with their own personal buffet and also provides me with a place to dispose of the earthworms and the rusty crayfish that I come across when I garden. The raccoons will eat them and they will bring their young to the area to teach them how to “hunt”. They like the water being in the little perform because they seem to like to dip everything they eat. This is how I do my best to address the earthworms that are here in my woodland areas. Earthworms that I find in my perennial gardens I leave alone unless they are leaf worms or the unmistakable big nightcrawlers and those I will toss in to the raccoon pond because they are a little bit too good at doing what worms do best. For what it is worth, I was able to grow White Trout Lilies (Erythronium albidum) here for the very first time two years ago by removing the worms from the area where I planted them. Ferns planted in areas of my woodland gardens where I have removed earthworms are performing remarkably better than ferns planted in areas that I never got to. People who garden in woodland areas might be experiencing difficulty establishing some types of plants because of the existence of earthworms.

Northumberland, United Kingdom(Zone 9a)

Sounds like a load of [email protected] to me . . . those articles can't even get the English name of Lumbricus terrestris (Common Earthworm) right. If they get that wrong, what else do they get wrong?


Madison, IL(Zone 6b)

Thanks Equilibrium. I will take some time and read the links that you provided. Up until reading the NY Times article, I had no idea that the worms weren't native. This is going to take some time to sink in. First the honeybees, now this. Geez!

Well resin, shall I throw a log on the fire for you... to bond with sofer ;)

Holland, OH(Zone 5b)

What say you this?

Holland, OH(Zone 5b)

And this? From the New York Times

IN THE GARDEN; The Dark Side Of a Good Friend To the Soil

Published: March 15, 2007
I'VE always thought of worms as my friends, until I started talking to ecologists who have been studying their voracious appetite for leaves.

''Your grandmother was wrong all these years,'' said Dennis Burton, an ecologist at the Schuylkill Center for Environmental Education in Philadelphia.

Worms may be good for vegetables and flowers, but for trees and shade plants they are a large and growing menace. In an agricultural field or a vegetable garden, worms help decompose organic matter, churning nutrients back into the soil. Their constant tunneling aerates the soil, creating pathways for air, water and plant roots.

But in forests in the Northeast and parts of the Midwest, worms are proliferating and consuming leaves at such a pace that they are actually destroying the duff, the thick leaf litter that nourishes tree seedlings, prevents erosion and protects woodland plants from disease and insects.

They are wreaking havoc in woodland gardens, too. Barbara and Robert Tiffany, who tend four acres of shade-loving plants at their home, MillFleurs, in Point Pleasant, Pa., have watched their prize-winning, four-foot-wide hostas shrink to half their size.

The Tiffanys first noticed that their hostas were shrinking two years ago. This was a crisis: they had promised to show off their 1,100 hosta cultivars to the American Hosta Society at its national convention last June in Philadelphia.

''I had no idea what was happening,'' Ms. Tiffany said.

They thought their water might be the problem, so they had it tested. But the water was fine. Then they noticed ''gazillions of worms,'' Ms. Tiffany said. ''Every time I would stick a trowel into the soil, worms would pop up or skitter away. They were so energized, not like the worms of my childhood.''

Mr. Tiffany did a little research and learned that the Northeast and the Great Lakes region were plagued by worms. They sent a few of their worms to Cindy Hale, a scientist at the University of Minnesota, who identified them as Amynthas hawayanus and Lumbricus terrestris, two species that are invading the Northeast.

The Tiffanys realized, in retrospect, that they had been helping the worms proliferate by carting in mulch for paths and top-dressing plants with compost.

They recalled digging up one prized hosta, a four-footer that had been reduced to two feet, and counting 19 worms as they fell from its roots.

The roots, normally so fleshy and vigorous, were stunted and sort of shredded, ''as if something had eaten them,'' Ms. Tiffany said.

''Earthworms were not meant to be in a forest,'' said Anne Bower, a conservation biologist at Philadelphia University who explained that northern forests evolved without worms. ''Their decomposers are fungi, microflora and fauna, which release nutrients very slowly,'' she said.

Worms arrived with the Colonists, who came in ships often weighted with rocks and soil, for ballast. The settlers brought plants, too, which carried worms and their eggs in plant roots. Over the centuries, of course, imported plants added to the exotic worm population; so did the fishermen who tossed their bait worms along the banks of streams and lakes.

In fact, the night crawler, Lumbricus terrestris, native to Europe and a favorite for baiting fish, is a big eater in the forest.

''It's an anecic species, a deep diver,'' Mr. Burton said. ''It burrows deep into the soil, pulling leaf litter with it.''

Another invasive worm, an Asian species, Amynthas hawayanus, is epigeic, meaning it stays close to the earth's surface, living in the topsoil and the duff layer.

''It's like a rototiller running around the surface of the forest,'' Mr. Burton said.

Both these worms, among others, have higher populations in urban and suburban areas than in rural areas. This makes sense, because they first came in through seaports and are often spread by gardeners who not only purchase their plants but also trundle mulch and compost into their woodland gardens.

The Asian genus, Amynthas, was first noted in New York and Connecticut in the late 1980s by ecologists working for the Institute of Ecosystem Studies in Millbrook, N.Y. They were trying to analyze the health of forests in a 100-mile radius of New York City.

These worms change the very chemistry of the soil, because their gizzards emit calcium carbonate, which acts like lime on acid soil, making it more alkaline. That may be nice for corn and sunflowers, but it is not good for azaleas and oaks, which thrive in acid soil.

The worms are also breaking down organic matter so quickly that the nutrient overload is injuring plants and running off into streams and lakes. Invasive plant species, like stiltgrass and garlic mustard, which thrive on heavy nitrogen, then move in.

How do you find out if you have too many worms?

Look for signs of invasive worms, such as a thinning forest floor or even eroded open spaces. Another sign is a noticeable lack of spring ephemerals like trillium, mayflowers and trout lilies, which are disturbed by all these tiny plows shifting the microbial community from fungal to bacterial.

To test for worms, mark off a section of your woodland garden or forest about three feet square. Then wait for a heavy rain (this test will not work in dry soil).

If the soil is moist, apply a hot Chinese mustard solution, made by mixing two cups Chinese mustard with 10 1/2 quarts of water. Sink five coffee cans, tops and bottoms removed, about an inch into the ground of the marked area, then pour the mustard solution into the cans.

''The mustard solution will go straight down and the worms will come up,'' Ms. Bower said.

If more than five worms pop out, you have a problem. In rural areas Ms. Bower's researchers have found only about two worms per three square feet; ''in the city we're getting 89,'' she said.

Ms. Bower and Mr. Burton have been testing various organic controls, like tobacco, walnut shells and pine needles. They were not effective. Sulfur pellets, however, mixed with oak leaf mulch, which is acidic, showed promise. Simply follow the directions on the back of the sulfur bag, and do not apply more than is recommended. (Soil that is too acidic will have its own problems.) Then spread out a couple of inches of the oak leaf mulch. The Department of Agriculture lists earthworms as beneficial organisms, so using a pesticide to kill them is technically illegal.

To avoid having so many worms in the first place, be sure not to feed them by spreading wood chips or compost in paths in the forest. Do not toss grass clippings, another favorite worm food, next to the woods, either. And do not toss out fishing worms or red wrigglers by throwing them on the ground or in a pond (they do not drown).

If worms are destroying your woodland plants and you have no choice but to kill them, they can be put in alcohol, frozen or collected in a bag and sent to the landfill.

I can hear the screams now.

Adrian, MO(Zone 6a)

I notice article refered to "no formal studies", "anecdotal reports", hmmm.If you are not planting trillium,spring beauty hepatica or goblin fern, or don't want to upset your groundnesting birds or salamanders, I wouldn't be too concerned. apparantly the goblin fern can't be found at all in periods of drought! I think someone just discovered that they had worms in the north and are probably blaming the worms for something that was caused perhaps by a drought maybe? who knows? they haven't even studied it yet. and some of these species don't just grow in the forest floor, some grow in meadows etc.
makes a good story though probably front page. and when they finally discover that the worms had nothing to do with this, well you'll never hear another word about it!

Holland, OH(Zone 5b)

In my specific locale I am not aware of any "worm" problems. I live 15 mi. inland from the Lake Erie shore. I was just relaying this information as relevant to the post topic. I was surprised to read that worms could ever be considered a problem. For any reason.

Adrian, MO(Zone 6a)

so now it's not global warming, it's worms!

Snapple's link may not have referenced "formal studies" but there does now exist enough research to begin implementing strategies to prevent the introduction of exotic earthworms to areas of the US where they do not currently occur. And there is certainly enough out there to take pro-active action by beginning to draft regulatory policy. I'm for it. For right now, I'll keep tossing them in my little preform for the raccoons. They find them to be a delicacy.

Atmore, AL(Zone 8b)

I don't know if earthworms are native here or not, but I sure have plenty of them.

Adrian, MO(Zone 6a)

perhaps in the form of an exotic earthworm tax.

Adrian, MO(Zone 6a)

they could package it with immigration reform

That was pretty funny... an exotic earthworm tax!

Adrian, MO(Zone 6a)

I just hope Al Gore isn't monitoring this forum.Ha

Oh my!

I can hear the screams now.
Snapple made a funny too and I didn't catch it until I re-read the thread!

Madison, IL(Zone 6b)

I sent an e-mail to our local Missouri Botanical Garden, so I'll see what the MGs there have to say. When I searched their website for earthworms, I got all positive information just as I have always believed -- the more worms, the better.

My area doesn't seem to have the type of forest floors which are considered threatened. Since I live in the American Bottom, our threatened vegetation is mostly wetlands and an entirely different ecosystem exists with a whole different set of problems.

Here's a link explaining how the different areas of IL were formed with all kinds of geological maps of IL showing the northeastern Great Lake area that Equilibrium has been referring to, and I'm located in the Horseshoe Lake area in the southwestern portion of IL. Big difference; not just zone wise.

I completely understand the whole northern forest floor worm thing and if I'm ever fishing up north, I'll wisely dispose of my leftover fishing worms.

Hopefully, I'll be planting the rest of my shrubs this weekend amongst the worms. : )

Kalispell, MT(Zone 4b)

I only have an opinion therefore not the knowledge of a scientific study. But I grew up in Michigan and often spent hours in the forests of out wetland and pastureland forests. They were where we dug up millions of night crawlers especially after a warm rain and thunderstorm. They have always been existing in the hardwoods of Michigan and have provided leaf and soil characteristics. I cannot believe what I am hearing. I will because I respect Equil read the articles and I must confess I do this with a prejudice towards the person and the science behind the studies. Though I agree why import worms and add them to your soils? I have more than I ever needed just providing compost and carboniferous material. Until then thank you my slimy wonderful friends.

Madison, IL(Zone 6b)

Have you hugged a worm today?

Presque Isle, WI(Zone 3b)

No, but I'm baiting a hook with one tomorrow! Ken

It's not just northern forests that are being hammered.

Our county extension office is loaded with Master Gardeners who all appear to be "worm huggers" so you are not alone from that respect greenbrain. Interestingly enough, the Master Gardeners up in Wisconsin are familiar with the issues. Our Forest Preserve District began distributing literature a few years ago so their volunteers have been apprised of the situation.

Hug a worm- eeew yuck! I'm getting this visual here! Best to use them on hooks!

Madison, IL(Zone 6b)

Response received from Mo Bot Garden. Not their area of expertise, but referred me to this link which offers some links that Equil may have already suggested.

In case, you're interested.

I just got home & saw a funnel cloud. Had to take shelter at a grocery store. Scary. I had just picked up my granddaughter from daycare. Here's the video clip if you're interested.

(See "Funnel Clouds Spotted In Metro East.")

Thanks for posting that. Now I am wondering what ever became of that inquiry. It would be very interesting to learn if the changes in earthworm species has led to any changing selection pressure on slime molds and if there are any documented genetic consequences.

Nice funnel cloud. You keep it down there by you.

Holland, OH(Zone 5b)

Equil, you know I've said this before, but my mother raised me such that if you say slime and/or mold in a sentence, in that same sentence, was always the word Clorox. In our house it was sometimes a verb. Clorox it!

I will be taking the Master Gardener class in Jan 2008. Finally have reduced my work load enough to allow it. (They put them all to work here doing a lot of rain gardens and phenlogy.) Should I just keep my mouth shut if I find myself in the presence of worm huggers?

Scott County, KY(Zone 5b)

You sure wouldn't want to have to eat those words...

Phenlogy, eh? Just teasing with you.

Based on my limited experiences with worm huggers, I'd keep my mouth shut. Take that back, I'd clamp my mouth shut and seal it with duct tape and go stand face forward in a corner. The few I interacted with did not like having their collective manufactured realities tampered with. They love their wormies and view them as beneficial and probably not in your best interests to suggest otherwise. Seriously, it's going to depend upon your instructor. If the instructor is receptive to someone like you interjecting that all wormies may not be created equal when the composting segment comes up, you're home free. If your instructor is into vermicomposting, well then you're probably going to be up against the old emotion v. logic. Might as well just take a 2 x 4 and bang yourself on the head a few times rather than going up against closed minded worm huggers lest you be perceived as wrongfully vilifying their helpless wormies.

Snapple, I suspect that even alluding to the possibility that worms might not be exactly as American as baseball and apple pie is going to be about the equivalent of hinting to ponders that Eichhornia crassipes might not be the best choice of a plant to add to water gardens any where on the continent of North America.

Kalispell, MT(Zone 4b)

I think that worms can be a source of pleasure in many ways. They tell me the health of my soil, my available nitrogen to be eaten, and the availability of nature using what we who love our slimy friends add to make their lives more fullfilled. I am a Pied Piper of the worm world and lead my slipper, slimy, and super soil swishers to a place they are appreciated. Where does Darwin get lost in a world of survival of the fittest. If they harm they only lead to their own extermination and the plants they feed on only dissapear and therefore they too are only another member of another Darwin award. This I have not seen in years exposed to the villanous night crawler. I think you who fear this creature who has lived in Europe for probably 75,000 years and now is coexisting here in our fair country for many years now have seen too many reruns of "Attack of the Killer tomatoes" movies. : ]

Ah but your slipper, slimy, and super soil swishers may not exactly be coexisting all that nicely.

I'm afraid that the world is a much nicer place with you in it than without you in it so please be careful with your role of the Pied Piper of worms lest you end up a mile deep in them on your property.

Here's a gastronomical treat-

Dredge the worm with seasoned flour.
Sauté in three tablespoons butter until browned.
Cover with sliced onions, pour over one cup thick sour cream, cover pot closely, and bake in a slow oven until tender.

Madison, IL(Zone 6b)

So what if the native fauna and flora wants to eradicate the non-native human species? Please don't answer, I'm only kidding! LOL

We humans are indigenous. We may be a little bit weedy, but we're native ;)

Madison, IL(Zone 6b)

It seems that the word indigenous adds to native, but native is not always indigenous. The words are not always interchangeable.

Reference Merriam-Webster dictionary:

synonyms NATIVE, INDIGENOUS, ENDEMIC, ABORIGINAL mean belonging to a locality. NATIVE implies birth or origin in a place or region and may suggest compatibility with it . INDIGENOUS applies to species or races and adds to NATIVE the implication of not having been introduced from elsewhere . ENDEMIC implies being peculiar to a region . ABORIGINAL implies having no known race preceding in occupancy of the region .

My younger-d went more in-depth, but I won't go there because it started sounding political/controversial. She keeps things interesting. ; )


We humans are all Homo sapiens sapiens. No splitting hairs there.

For plants the words are always interchangeable. Our native plants forum is referred to as Indigenous Plants where other on-line forums refer to them as Native Plants. This was by design. It was an attempt to avoid conflict.

Madison, IL(Zone 6b)

My point was misconstrued, but that's ok. It really wasn't worth mentioning.

Well, I think that I learned quite a bit here from all of you. A special thanks to those of you who took the time to provide the links to back your responses. It's great being rather new and receiving so much feedback. For some reason, I was afraid that no one would respond.

I enjoyed reading the opinions of folks based on their own personal experiences. Sometimes experience is the best teacher.

Oh my gosh greenbrain! You are new! Welcome to the forums!

Was it my Alsatian smothered worm recipe that made you feel right at home?

Kalispell, MT(Zone 4b)

My only reference is this: So again I am only a homo sapiens sapiens who has an affinity to observe and conclude. I rarely read and believe. Motives are hard to understand. Until I observe this issue otherwise I shall remain (pro-worm) and not fear full of everything I read. None of the above articles report discussion of other views, therefore I suspect their prejudice. Sorry Equil, the first time we disagree. Internet can deceive those who don't question. (My assumption) Steve.

There's nothing wrong with one's only reference being their own garden and your photos, as usual, are show stopping. And one most certainly can't believe everything one reads online either but... there is a mounting body of scientific evidence out there suggesting that the introduction of non-native earthworms was not in the best interests of the ecosystems.

I only reference this particular article because I was most curious about any ongoing research related to altered fungal levels. I'm going to be on the lookout for new and innovative ways to manage exotic earthworms while I plug along restoring my property-

As with anything else, more research is needed.

Madison, IL(Zone 6b)

That's nice that you're keeping a diary Steve. I need to start taking advantage of the journal features. My dh & I have decided that it's time to purchase a digital camera so that I can save photos of my works in progess. Since my hubby plays in a band & is always taking promo shots, he'd also benefit. I'm suggesting that we go shopping this afternoon. If I disappear from the forums for a bit, you'll know that I'm busy with my journals.

Equil, you popped right in & invited me to the roundup only 2 weeks after I subscribed. You made me feel right at home. I also received the same friendly treatment from you the very first time I posted & it was on the "trees & shrubs" thread asking what everyone ordered in woodies. I did fail to mention that I was a newbie. For some reason, I assumed that it was obvious. Now that I'm more aware of the vast number of davesgarden members and subscribers, I know that it's not so obvious. When exactly would someone no longer be considered a "newbie"? I joined on 2/4/07. Anyway, the "Miss Congeniality" award goes to you--that's just my opinion.

I've been too "chicken" to visit the chatroom. This is my first experience being on a forum. However, I made a new gardening friend that I met out plant shopping yesterday (2 azaleas & 2 rosebushes) & told her about davesgarden. She's never heard of this site & said that it sounded like something she'd like to try. She's already invited me to checkout her yard (I just happen to pass by picking up my gr-d from daycare) & I've offered to drop her off a pot of lemon balm. She's new to this area (& this country) & has a lot of gardening questions. The librarian I chat with every Sat. (my next stop after plant shopping) also is going to check out this site. She just ordered an "earthbox" of tomatoes & wants to know more about them. Maybe I've recruited two new members from this area?

Maybe I've recruited two new members from this area?
That's how it works! And, you probably did just recruit new members! Good job. I've recruited a few here and there over the years but this site is so big I never run into them. I know one of them frequents Perennials and another frequents Garden Talk while another frequents Roses. I don't go to any of those forums yet friends that I know in the flesh are in them regularly because when I see them we talk about what we've read here. Funny how that works when a neighbor or somebody from work is in the same forum and you never run into them.

I popped in and invited three people to that Round Up who were from Illinois or Wisconsin. It's a great opportunity to meet people and it was a blast last year. The plant swap is phenomenal and the food people bring is great! It's looking as if 3x as many people are attending this year than last year which was the very first year and ten to one odds even more will attend next year which will be the third year. Unfortunately, I now know you are way down by Missouri so that would be a haul for you to get into central Wisconsin. Maybe next year?

When is someone not considered a newbie? Good question. In my mind, I'm thinking after maybe 6 months or so???

I've disabled scripts and such on the computers here because of kids getting into chat rooms. I've been to the DG chat here before. It is my first and only chat room and I'd allow my kids in there. It's totally safe and you will run into some really cool people. Don't be chicken. Next time you see that the chat room is open, log in!

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