Pill bugs: beneficial pruners or garden detestation?

I have been using a lot of wood chips as a soil conditioner. They work great for that purpose but at what cost? I now have a lot of pill bugs. Not a problem, or so I thought. They are just there to eat the dead or decaying chips, or diseased plants. Right? Maybe not. I have transplanted healthy plants only for them to be mostly eaten the next morning and completely gone the morning after. I’ve even transplanted into pots with sifted compost and wood chips as mulch with the same results. It’s to the point I want to scoop up the chips and use them as mulch around my trees or a garden path. But do I need too? What am I missing?

I have seen many people here on Permies who were convinced that pill bugs ate their seedlings.  However...

All the solid-looking authorities I can find on the internet are in agreement that they overwhelmingly focus their diet on decaying plant material, turning to tender greenery only when they are close to starvation from lack of preferred (dead) foods.

I myself mulch with wood chips, my garden pots and containers and beds are full of pill bugs, and I have never seen one so much as touch (much less eat) a live plant.  I have been watching closely/intently for a couple of years now, because of (what I see as) the false accusation.

Thus I am, and remain, highly skeptical of the idea that pill bugs eat seedlings.  There are many other tiny creatures (various insects, leetle birds, and eensie rodents) who are, in my mind, more plausible candidates.

i suspect slugs in this kind of situation.

Thanks Greg and Dan. I’ve used two kinds of compost this year. One is chicken compost that’s sifted and the other is something else 😂. It’s a mix of all kinds of wood chips, rabbit poop, grass clippings and coffee grounds. Everything I’ve planted in that compost has died. It’s absolutely loaded with life! The Most worms I’ve ever see, and pill bugs. I’m sure there’s more but that’s what I can see. Seeing bad results I put some in pots with seedlings and seed. The seeds never germinated and the transplants died in short order. The only insect I could see were the pill bugs. I agree with you as far as their normal diet and not something I’ve even been concerned about. Sticking with my normal compost and waiting another year on the other. Thanks guys!

Scott,  are the items you mentioned in the second compost still recognizable?

The only thing that’s recognizable is the wood chips.

Red handed. Three year old healthy strawberry plant.

I’m guessing they have been wounded by a slug and the pill bugs were there just to finish off. I don’t know what’s up though. I am frustrated by a new onslaught of problems that I haven’t had since starting permaculture. I have never had slug issues until now and I see a lot of them. I now also have a ton of frogs, worms, garter snakes and pill bugs. I’ve always trusted the permaculture way of letting nature work things out. It took five years to grow a successful pumpkin or squash. I now have vigorous seed that no amount of squash bug pressure can derail. Thanks for all of your input and I welcome more thoughts.

I have seen pill bugs eating strawberries and the stems of bean plants. Because we also have slug and bird pressure, I can't prove that the slugs didn't start the process and the pill bugs didn't finish it, but I am quite sure that in my ecosystem, pill bugs can be a problem. One local grower's solution was to put a ring (he used sliced PVC pipe and I've been looking for a better alternative) which he wraps in duct tape with the sticky side out. The pill bugs get stuck to the tape before they get to his transplants. I was wondering if I could find a way to use tangle trap instead, as duct tape is made of polyethylene as the first layer, unspecified "fabric" as the middle level and rubber adhesive as the sticky part (according to the web). I am trying to decrease my use of plastics where I can (it's a slow process in a climate where everything natural rots sooner than I want it to!) That said, if the wood bugs got the tomato plants I just planted yesterday and protected from the slugs with a ring of crushed egg shell, I may break down and use plastic this year and work on alternatives for next year!

Oh, I remember the 'pill bugs don't eat seedlings' conversations

My experience is that pill bugs DO eat seedlings.  I don't know if it's only under certain conditions or if there is some damage that leads them to the leaves but YES! pill bugs have eaten some of my seedlings.

I did not film them in action although my husband is a witness...and our son!  
They were actively up on the young leaves, chewing away...gobs of them

I have seen pill bugs on strawberries, but they are almost always working away in bites that look like they came from slugs, snails, birds, or weevils. I have also never seen them on strawberries without the other species present and clearly doing damage themselves.

I speculate this is another way that the "Paul Gautchi/Back to Eden Method" requires running the wood chips through a chicken and/or duck run before using in order to be fully successful. The chickens substantially reduce the starting population of pill bugs, as well as slugs and weevils. It would be an interesting experiment to run separate beds with chicken run woodchips vs unprocessed chips. I am doing one unscientifically in the food forest I manage remotely, where domesticated birds have not been practical to keep, vs my old property where most chips went through the chicken and duck run. I am seeing drastically higher slug/snail populations, as well as many more pill bugs (though those are mostly under larger woody debris).

I am trying to replace the chickens and ducks with wild birds and amphibians I provide habitat for on the site, and they are dramatically increasing with their songs all around to show for it, but the slugs and snails are still insane right now. I pulled 50lbs of terrestrial gastropods off 2000sq ft of hugel beds in one week! I was able to drop them at my friends' places who took on my old birds, but it is really hitting our greens harvest, and it feels like I have slugs tattooed to my eyelids at night. I am inclined to think the pill bugs are just finishing their leftovers. On the bright side, my birds loved them even more than slugs.

I like what you’re doing there Ben. I will read your post several more times to make sure I take it all in.
The person all of this keeps me thinking about it is Masanobu Fukuoka. I’ve read that he viewed aphids as beneficial pruners for weaker plants. I’m hoping that’s what’s happening here.
Your idea of letting the chickens have their way with the wood chips is very smart. I will certainly do that next time.

This is the first strawberry I’ve harvested this year. I’ve started putting any berry that’s approaching ripeness on cardboard. All of them are still intact. I have some plants in beds that are only mulched with shredded leaves. All of them are untouched without the cardboard. Definitely something in the wood chips. Hope this helps!

I've long thought that pill bugs ate my bean plants. I'm going to try to be really observant this year.

In my garden, slugs tend to be the destroyers of seedlings, but the pill bugs will go after damaged parts of the stressed plants.  I had pill bugs swarming over a poor nearly eaten squash plant a couple weeks ago, and initially thought they were the culprits.  Once I shoed them off I saw the slime trails though.  I think once plants get stressed enough it triggers the pill bugs to treat their wounds like decaying matter.  I do a slug walk through the garden at night a couple times a week, and it is pretty crazy the number of slugs that exist in a small, 25'x25' plot, and most of them are very well hidden in the daylight.

Pill bugs do go crazy over fruit if it gets even slightly bruised, though.  Many a fallen plum has been made less appealing looking by their chomping out of the bruised bits.

Yea, I could be wrong. I have never had a slug problem here. I’m not sure what’s going on or what to do about it.

Before this spring I would have been right there with everyone insisting that kill bugs are mostly harmless. My home garden has tons of them around and I have never seen them cause any harm.

However, the farm I work at has had an insane pill bug outbreak this spring. I have personally witnessed them actively eating the leaves of young plants and they probably took out about 10% of two large greenhouses. They did target unhealthy transplants at first but once they really exploded they also have attacked otherwise healthy seeming plants. To be fair, the person in charge of our ipm (who has been replaced in part due to this situation) really dropped the ball and didn't implement any of our program really.

One other interesting observation that I don't have a solid explanation for, there are lots of slugs (and their attendant damage) in the home garden, there are approximately zero slugs out at the farm

As a big wood chip proponent, I will also attest to the fact that the chips make a perfect home for pill bugs, and that yes, they do eat living plants.  Once the plants are a bit larger they tend to leave things alone, but they can wreak havoc on seedlings.

But I still think wood chips are the best thing for the garden since . . . sliced wood chips.

I've had terrible pillbug problems develop from using wood chips and woodchip-based compost. I stopped using it because of that issue.  I've caught them in the act of eating all sorts of seedlings including small transplants.  I looked at them very close up - they were definitely eating the plants.  Lettuce transplants would be gone in a couple days.  They seem to like plants very tender.  

At the time, we had cedar raised beds full of the woodchip-based compost.  At it's worst, you could find thousands of pillbugs along the edges of the cedar inside the beds. They made little burrows that concentrated at the edges.

Those beds could grow very little until we figured out something to do with the pillbugs.  Incidentally, we could grow asparagus, garlic, artichokes or cardoon, tulips, echinacea, and a few other medicinal herbs and flowers without issue in them. So strong flavored or bitter plants seem to not be on the pillbug's favored menu.

We dealt with the problem by teaching a pet bird to eat the pillbugs. Turned out they are delicious, according to her reaction.  They became a favorite food.  Once we figured out she liked them, we'd put her in the garden beds and she would gobble them all up. In the process of teaching her to eat them, wild birds watched and learned!  After that, the wild birds took care of most of them and the problem faded.  That was a fascinating experience because I'd never seen wild birds eat them before.  But now, in the deep forest of western Oregon live a group of birds who like to dine on land shrimp.  :-)  Hopefully they will spread the word.

Kim Goodwin wrote:

Incidentally, we could grow asparagus, garlic, artichokes or cardoon, tulips, echinacea, and a few other medicinal herbs and flowers without issue in them. So strong flavored or bitter plants seem to not be on the pillbug's favored menu.

That makes me wonder if you were to put some of those leaves in a blender and make a fairly strong "drench" for the wood chips just before planting/transplanting seedlings, would that be enough to discourage the pill bugs until the plants were large enough to cope with some pest pressure?

Very interesting to read about birds learning to eat pill bugs! I have serious pill bug problem too. They not only eat young seedlings, they are eating compost I put down too. I raised chickens hoping they would feed on the pill bugs but that was not happening. I need to figure out how to train them to do that too.

Jay Angler wrote:Kim Goodwin wrote:

Incidentally, we could grow asparagus, garlic, artichokes or cardoon, tulips, echinacea, and a few other medicinal herbs and flowers without issue in them. So strong flavored or bitter plants seem to not be on the pillbug's favored menu.

That makes me wonder if you were to put some of those leaves in a blender and make a fairly strong "drench" for the wood chips just before planting/transplanting seedlings, would that be enough to discourage the pill bugs until the plants were large enough to cope with some pest pressure?

Wow, that's a neat idea.  I grew cardoon mostly for composting anyways. They are so productive. It would be easy to try. I don't live in Oregon anymore, so someone else will need to! I'm in the desert SW now and the only places I've seen a pillbug problem are where - drumroll -people have tried to "amend" the desert soil with lots of chip-based compost!  It's so predictable, once you know what to look for. That wood-chip/bark compost is never fully composted, too. I've found there are always splinters. Once it's fully composted, the pillbugs seem to diminish.

As for how to teach a bird to eat pillbugs - if you are doing this with semi-tame chickens or ducks, here's one way I've experienced. Let the chickens loose while you work in the garden, digging specifically. Like with a fork or shovel. See if any of the chickens pay attention to what you are doing.  Throw some a few worms or bugs you encounter to get their attention, and see who sticks around. If one sticks around and starts to watch everything you do with that shovel or fork, that's what I call the Smart Hen. (Or cock, etc...)

If you have a little smartie-pants that one will start following you around in the garden and watch carefully for everything you expose. That one is usually a little more intelligent or trusting or both. You can feed him or her new things, like pillbugs, and they will usually get enthusiastic about it and then do it themselves. Some people think chickens are all alike, but in my experience they have wide ranges of intelligence and comprehension, curiosity and motivation. And it's easiest to teach the one who shows the most curiosity.  Over the years I've had a female smart duck, a smart hen, and a delightful little smart rooster like that as well.

My husband added a couple points about teaching birds to eat pillbugs.  It would probably be easier and more effective to start with a chick. Ours was a young bird.  they are developing tastes around that time.

Also, he suggested collecting a bunch of pillbugs and putting them into adult chicken's food, so they might all get a taste.  However, that would only work if you want to let them all go in the area of the garden with the pillbugs.  

I find it rather destructive to let a bunch of chickens loose in very many areas of a garden, so I found it easier in the past to figure out who was the smart one and just let that one do the work.  But we have had lots of success with loose ducks in the garden, as long as plants are above seedling stage.

Kim Goodwin wrote:I've had terrible pillbug problems develop from using wood chips and woodchip-based compost. I stopped using it because of that issue.  I've caught them in the act of eating all sorts of seedlings including small transplants.  I looked at them very close up - they were definitely eating the plants.  Lettuce transplants would be gone in a couple days.  They seem to like plants very tender.  

The question is why do you grow lettuce with wood chips? Wood chips create fungal dominated soil, while lettuce prefers bacterial soil.
So maybe the pill bugs felt that the plant was in the wrong environment?


Also fascinating stroy with the bird, what species is it?

R. Han wrote:
The question is why do you grow lettuce with wood chips? Wood chips create fungal dominated soil, while lettuce prefers bacterial soil.
So maybe the pill bugs felt that the plant was in the wrong environment?

Most of my gardens are covered in heavy layers of wood chips, and all grow really well.  All of them would be covered if I had enough chips, but some of my garden areas are pretty large and it takes a tremendous amount of wood chips to cover a garden to depth.  

See "Back to Eden" movie for more information about growing in wood chips.  There are quite a lot of people, here and elsewhere, that do it.

I keep some species of isopods (pill bugs) as pets believe it or not, and I have noticed that they will only eat green plant material if they have nothing else to eat, and that they eat decaying vegetation before eating green material. I feed them scraps from our leftover veggies from time to time.
Their favourite is dead tree leaves, it seems to get them “ in the mood” if you know what I mean 😏.

Donald Smith wrote:I keep some species of isopods (pill bugs) as pets believe it or not, and I have noticed that they will only eat green plant material if they have nothing else to eat, and that they eat decaying vegetation before eating green material. I feed them scraps from our leftover veggies from time to time.
Their favourite is dead tree leaves, it seems to get them “ in the mood” if you know what I mean 😏.

Are you willing to test the "if it's too dry" theory, gently with your pets? Give them only quite dry dead stuff (like my farm in the summer drought) and a live plant and see how they react? Please don't push it to the point you hurt the little guys - experimentation doesn't need to be nasty!

Jay Angler wrote:Are you willing to test the "if it's too dry" theory, gently with your pets? Give them only quite dry dead stuff (like my farm in the summer drought) and a live plant and see how they react? Please don't push it to the point you hurt the little guys - experimentation doesn't need to be nasty!

The dead leaves I give them are bone dry and they eat it dry, but I’m going to toss in some small seedling lettuces and see how they react.
I have quite a few in there right now so it will be interesting to see.
I keep some pill bugs with my corn snake because they help keep the terrarium clean by eating the snakes poop, I also have live plants in the terrarium and they don’t touch them.

But keep in mind that there are many different species of pill bugs so they might behave differently.

Update!
So, I grew some lettuce seedlings and tossed them in with my huge isopod (pillbug) colony.
They ate them... however I realized that they may be hungry because there wasn’t any other food in their enclosure so I tried again but this time after feeding them other foods they enjoy ( dried leaves, turtle pellets and a powdered insect food for crickets). I waited a day so they could fill their tummies and put some more lettuce seedlings in.
They didn’t touch them until all the other food was gone and then it took a few days, I just noticed the seedlings were gone today.
I would guess if they are well fed they tend to prefer dead matter like compost and whatnot, as I have noticed in my snake terrarium they don’t touch the live plants just the pieces of dead leaves and poop.
The species I used in this experiment is Porcellio scaber, a very common wood louse found all over North America that doesn’t roll into a ball.
I also have some armadillium species which is the kind that CAN roll into a ball (so cute!) which I’m going to try next.

Update!
I added a young lettuce leaf to my other isopod colony, the one people refer to as rolly poly, and they barely touched it after three days. I used a leaf because my seedlings are all old now and I didn’t want to sacrifice the whole plant, but I figured it would work the same nonetheless.

I also added a pic of my other sow bug colony just...because 😉.

Does this mean that they won’t eat your seedlings in your garden? Probably not, but I think it shows that green plants are not their preference and it may be a last resort food for at least some of the isopods out there.

Wow Donald - thanks for the pics. Have you ever added the frass to a seed-starting mix? A friend once brought me black soldier fly frass and it was recommended for that use.

Jay Angler wrote: Have you ever added the frass to a seed-starting mix? A friend once brought me black soldier fly frass and it was recommended for that use.

I used some in already established plants but I’ll try adding some to some of the smaller tree seeds I’m going to plant this year, thanks for the advice!

Update here. I have a cinderblock raised bed and lots of pillbugs were hiding inside the blocks. I offered some to my five chickens and two were interested and started eating. Hopefully that will keep the pillbug population in check.

Donald Smith wrote:I keep some species of isopods (pill bugs) as pets believe it or not, and I have noticed that they will only eat green plant material if they have nothing else to eat, and that they eat decaying vegetation before eating green material. I feed them scraps from our leftover veggies from time to time.
Their favourite is dead tree leaves, it seems to get them “ in the mood” if you know what I mean 😏.

My husband also has pet rollypollies/woodlice/potato-bugs! He and our kids think they're really adorable, and are trying to breed them for specific traits, etc.

I wonder, what would happen if the plant was growing in stuff they considered food?  A lot of my garden beds are made of poop, wood, compost and leaves...all the sorts of things that these little guys love. What if they're happily munching on their food and there just happens to be a root of a plant in it?

Maybe the problem is that many of us in wet climates have super happy pillbugs that keep getting population explosions that result in them eating stuff they wouldn't otherwise eat?

MY SOLUTION TO PILL BUGS
10 years ago I moved to Sedona, Az and began turning my 1 acre plot into  an heirloom, organic garden with dozens of beds. The 2nd year I was attacked by earwigs that ate everything in sight. Took me all summer to get them under control but it was doable. I noticed tons of pill bugs but they weren't bothering my crops that year so I ignored them. BIG MISTAKE! The next year I had a Super Explosion of pill bugs. They ate almost everything (except my tomato plants and carrots). I'd plant out seedlings and the next morning they would be gone! I would just find piles of pill bugs! And I couldn't stop them. Millions of them! Some have suggested that my garden must be out of balance. Yes, it was! I was amending my soil and trying to garden in high desert country, providing food where there had only been cactus and scrub oak before! The bugs found heaven and began procreating like crazy!!

I tried every suggestion I found online. Most of them like D.E. And Neem oil were useless. Some were slightly effective.... Place grapefruit rinds or cardboard down, lift them up in the morning and step on the bugs, sink a soup can down into the dirt and fill it half way with beer then dump out the dead bugs, sprinkle coffee grounds around the plants. I couldn't possibly drink that much coffee, the cardboard didn't attract enough of them, I really don't like grapefruit all that much and the beer worked great but would have cost me a fortune! I really had millions! And nothing here seems to like to eat them.

It took me 4 years to finally get them under control but here's what I did. I learned to practice really good garden hygiene all the time, even now that I don't see too many, because they come back quickly.

1. I took away all the mulch they live under. It's 100+ degrees here all summer and I would love to mulch, but I can't because they quickly come right back. I plant things together so they can shade each other.
2. When I pull my plants at the end of the season I remove every scrap of the plants and roots and even the weeds and leave the soil bare. Nothing to eat, nowhere to hide.
3. I moved my compost pit as far away from my beds as possible.
4. I don't bring my compost up to beds until it is 110%  finished, till it looks and smells like great dirt and has no bugs in it.
5. I found one organic insecticide that works, Spinosad. It's not cheap but a quart makes 16 gallons. I spray my seedlings and a few inches of the dirt around them the minute I plant them and then every 3-5 days for the first 2 weeks or so. Then they have a good chance of surviving. Then I watch over them like a hawk and spray whenever necessary.
6. The minute I see my peas or beans coming up I spray those beds with Spinosad too, same as the others. Spinosad is made by several companies. You can find it at any garden center/hardware store.  Sluggo Plus contains Spinosad but is not as effective. I would need to use a lot of it.
7. I always trim off the leaves from the base of every plant when they get big enough so that I can clearly see every stem and watch for trouble. Spray when necessary.
8. Plants in the squash family are their favorite. I thin the leaves on these too so that I can see the stem and once they start to grow well I place something under the vines to keep them off the dirt as much as possible. I use rocks or sticks or pieces of wood, whatever I've got.
9. Similar to cardboard I make traps out of old 1-2-3 gallon pots. I place some rocks and  and a little dirt in them (2-3 pounds seems to be the weight they prefer) and place 1-2 right next to the crops they love. As I water my plants each morning I lift the pots, step on all the bugs under them and spray them with water to keep the soil moist.

This took awhile but it is working well for me. So..... ANYBODY HAVE ANY GARDENING SOLUTIONS FOR CLIMATE CHANGE BECAUSE THIS IS BLOWING MY MIND!

When it comes to gardening I say never say never.  Depending on conditions One person can swear pill bugs never eat seedlings, and another person can say they do.  Funny thing is they can both be right.  There are so many variables we deal with in the garden no two are alike.  I am a huge believer in using wood chips.  I have often sung there praises.  So it concerns me to hear so much negativity towards using wood chips.  Like I said in the beginning nothing is for everyone, and wood chips may not be for you.  I would recommend trying a few alternatives before removing all your chips.  I would try diatomaceous earth first.  A circle around your seedlings, as least if it doesn't work you know its safe.  You have to be part detective when you garden.  One year I couldn't get my corn to grow.  I ended up putting tinsel on sticks, and sprinkling the bed with cyan pepper.  What one worked? I don't know, but one did. ( I know some will think I'm terrible for using cyan, but I figure it doesn't do any lasting damage, and it teaches the little critters to stay out of my garden.)  It's often just a matter of trying stuff until something works.
As far as chickens in the garden, unless well supervised that is a recipe for disaster.  I'm extending my veggie garden, and adding two hugel beets.  Right now my chickens can get out of there yard.  The good news is I probably have a lot less pest in the soil.  The bad news is no matter how I tried to protect my pea seedlings, the chickens still managed to get every last delicious morsel.  They are so happy I grew those seedlings for them.  Chickens are scavengers.  They eat anything and everything.  It may be benafical to let them loose before you plant, or when all is said and done in the garden, but while you are actively growing veggies you want to eat, it's risky business to invite your chickens in.
Sorry about your trouble, I hate it when I see the perfect ___ and I turn it over to see bugs, or birds, or something got it before I did.  Very frustrating.  Good luck to you.

Very enlightening thread! I am happy I found it.

So, I presume for a previous mention that pill bugs love moisture? We have been having an unusually rainy season (I say as we currently have flash flood warnings). I guess that's why the bugs are out of control... and also perhaps because it is my second year doing wood chips as mulch. I really NEED the wood chips living in Texas, just... I guess I could had moved them until late June. But why make more labor...

Does anyone think my pill bug problem could be related to trying out Ruth Stout composting? (Putting the food waste directly into your garden)
I did that.. oh perhaps in January. And actually the squash growing there now came out of that compost. When I planted in this garden bed this past month in other locations it seemed all the food waste had turned to dirt. But I guess it could had attracted the bugs, along with the mulch, causing them to now eat my squash.

It's just strange they didn't go after it until it got quite large and my seedlings are okay. I guess maybe slugs weakened it first.

I currently don't use my coffee grounds, shamefully, so I'll try sprinkling that around the base. Does it deter slugs, too?

I've read pill bugs mostly eat decaying and decomposing matter. So it stands to reason compost in the garden may draw pill bugs.  
Coffee grounds are supposed to help with pill bugs, snail's, and slugs.  It couldn't hurt to ring your problem areas with it.  
One tip I saw was to cut oranges in half and put them cut side down in the soil, or wood chips at night. In the morning you should have lots of pill bugs on the orange. Dispose of them, and use again.
Another tip are several essential oils.  Mint was one of those mentioned.  Makes me wonder if you plant mint if it might help.  (Mint is very invasive. If you decide to try it, make sure to put the mint in another pot.  I took one of those larg black pots you get when you buy a nursery plant. Put it in the soil with a couple of inches out of the soil. This lets me grow mint with my veggies without it taking over.)
Good luck to you. Normally I don't think pill bugs are a big problem in the garden.  It's when for what ever reason the balance is off, and there's way to many.  Maybe instead of trying to get rid of them, try to encourage frogs, toads, or Bird to visit your garden.  Let them balance the numbers?
Like I said before, you just have to keep trying until you find what works for you.  Good luck