Worm Towers: Right Idea, But the Wrong Product?

Worm towers or worm tubes are an intriguing idea for turning food waste to worm castings.

Normal worm composting requires the worms, bedding, and food to be placed in some enclosure only to require you to harvest the castings.

But the worm tower is a “permaculture” innovation designed to allow you to recycle food waste and create worm castings without ever leaving your garden.

(Note: You may searching for a commercial worm tower like a Worm Factory 360 or Vermihut. If so, I’d like to ask you to explore a far more breathable worm bin that we manufacture called the Urban Worm Bag! Check it out here!)

Firstly, What Is a Worm Tower?

A worm tower is normally a 4-inch PVC pipe with holes drilled in the bottom 12-18 inches, which serves as the below-grade portion. This supposedly allows worms to go and come as they wish, much like an Amsterdam hostel, minus the patchouli smell.

The theory holds that the composting worms will enter the worm tower, eat the food waste, depart the worm tower, and deposit worm castings around the garden, aerating the soil in the process.

At first blush, it is a fascinating concept and probably attractive to gardeners like my wife, who don’t care to handle worms.  Just toss in your food waste and watch the garden take off.

Excited by videos like this, I was initially very excited about worm towers, even to the point of researching the costs of manufacturing them with recycled plastics.

But I asked a Philadelphia-area composting and horticulture expert about it and got a little tough-love and mocking in return.

After listening to his arguments, I’m convinced this idea has serious flaws.

The case is straightforward.

The Case Against Worm Towers

Worm Towers Are Inserted Into Soil and Composting Worms Aren’t Soil Dwellers

Worm tower buried in ground near a sidewalk
Composting worms will not be able to work through compact soil

Red Wigglers and European Nightcrawlers, the two most prevalent compost worms in temperate climates, aren’t burrowers.  Both of these worms live near the surface in loosely-packed material like leaves.

In other words, these are the oddball worms that don’t like dirt.  So you can’t expect them to eat your food waste, leave the worm tube, and do their business next to the heirloom tomatoes.

And the larger Canadian Nightcrawlers that do like to burrow in soil don’t swarm food in the manner necessary to process any significant amount of it.

This is a problem because a PVC worm tower stuffed with food waste will not turn into black gold.

It will turn into a PVC pipe filled with rotting food.  And in the process, it will heat up, attract pests, stink to high hell, and may earn you a picketing from the local chapter of the Composting Worm Union for horrible work conditions.

Worm Towers Lack Surface Area Which Is the Key Metric for Vermicomposting

The best stocking density for vermicomposting worms to process food is approximately 1 lb per square foot of surface area.

This number is independent of depth; a 5-square-foot bin will accommodate roughly the same number of worms whether it is 24 inches tall or 10 feet tall.

PVC worm tower laying above ground
4-inch PVC is the largest commonly-available size of PVC pipe for worm towers

The largest PVC pipe available to laypersons like you and me is 4 inches in diameter, the size of the largest waste lines leaving standard residential homes.  It is also the size featured on almost all YouTube videos touting the worm tower.

So let’s do the math.  A 4-in diameter pipe will get you a whopping 12 square inches or about a twelfth of a square foot.   At 2 lbs of Red Wigglers or European Nightcrawlers per square foot, this worm tower will accommodate a sixth of a pound or 2 2/3 oz. of worms.

Assuming worms can eat 50% of their weight daily (and this number may be very inflated), this means our lovely PVC worm buffet will process a whopping 1oz of food each day, assuming ideal conditions.  And a worm tower in the hot sun or pouring rain will not be enjoying ideal conditions.

(Update:  2lbs per square foot is far too dense for the beginning vermicomposter.)

So if you are planning to use worm towers to feed your worms in situ, you will have to accept one of two things:  you will process very little waste, or your garden or yard will look like a graveyard with cylindrical headstones.

A marginally better idea is a 3- or 5-gallon bucket, which will net you around ¾ of a square foot of surface area. 

I did this with a little success, hosting some native worms in my garden

But I still didn’t vermicompost food waste with any efficiency.

That PVC Worm Tower is Not Green!

Yes, PVC is used commonly below the ground in all sorts of residential and industrial applications. 

But PVC strands for the less benign-sounding polyvinyl chloride.

This was never meant to have anything but its waxy exterior exposed to soil.

And by cutting the bottom and drilling dozens of holes in its sides, people are exposing the soil in their gardens to vinyl chloride, labelled a Group A human carcinogen by the EPA.

I am always impressed by the ingenuity of those leading the “permaculture” movement.  I constantly see innovations that require forethought, creativity, and a willingness to be different.  But like New Coke and Clairol Touch of Yogurt Shampoo (yes, it existed), some new ideas aren’t destined to succeed.

Sometime they fail for reasons of insufficient consumer education and marketing.  Other times because of simple math.

I believe my former vermicomposting muse, the worm tower, is a well-intentioned, but misguided idea because of the latter.

Maybe There Are Better Options?

Now as a manufacturer of a worm bin, I may not be the most neutral party here. But I do think picking up the Urban Worm Bag with discounted accessories and creating castings on your own may be a far better option! (This article was originally written in 2014 and I didn’t launch the “UWB” until 2018, so this has been a long-held position for me!)

For a larger in-ground solution, the Subpod is also an option!

Agree?  Disagree?  I look forward to your comments and personal experience with worm towers.

157 thoughts on “Worm Towers: Right Idea, But the Wrong Product?

  1. Your article makes perfect sense. I had forgotten that I had read composting worms don’t burrow in the soil, but I did recall earthworms don’t eat food waste. It’s interesting that I just read an article by a respected permaculture group on how to make one of these worm tubes, though they did point out to use red wigglers. I’m new to permaculture but it seems that careful, well though out planning is a big key in the practice.

    I did not know about the coating on pvc and about pvc-soil contact. Thank you. One more thing I learned is another reason my recent experiment with worm composting indoors failed. I thought I knew – well I know part of what I did wrong, now I know more. I’m glad I found your site and blog!

  2. I have to disagree. I’ve been using my worm towers for around 6 months, perhaps a little longer and they have been sensational. Everything that grows nearby has flourished, they do not smell and my 3 worm farms that are I guess around 4 inch diameter each and 30 cm deep (the bit covered in the garden) gets rid of around 20 – 30% of my food waste. We are a family of four and I am ashamed to say that we are often quite wasteful, not getting around to eating things, so 20 – 30% of our food waste is a lot. It includes things like watermelon skins, tea bags, the works. I have had what I assume are some possums trying to dig in to get to the food, but they haven’t succeeded and I just fill in any holes that they make. I admit that I am now finding that the farms are filling up with compost and I suspect that I will soon need to start again, but it has been well worth the effort.

    1. Sometimes people are JUST TOO SMART for their own good. They believe the “expert” that ONLY HAS BOOK KNOWLEDGE.

      1. Steven,
        I try to keep things friendly around here. I don’t mind disagreement, but you’re tipteoing into insult territory.

        This is *my* site and comments are approved and disapproved by me, the Urban Worm Company’s benevolent dictator ;). I’ll let the comment stand, but please keep the temperature down.


        1. It’s unbelievable that you have to receive rude comments like that, I found your article intelligent and informative! I’d previously watched a YouTube video of someone making and adding a worm tower and couldn’t understand how they would be employing the most efficient compost producing worm, the tiger worm when it’s a surface dweller. I am trying to find the best way and think rather than a wormery, I want the best for my worms, I somehow make it so they have freedom to come and go from my raised vegetable patch but choose to stay, some sort of trench system. I need to find the best way to keep them warm enough in winter! I want them to be processing humanure as well as food scraps, they will only be given organic material so I won’t be using paper or cardboard but will give them leaves for the carbon rich amendments. Thank you for your great article!

          1. Thanks James! Yes, trench vermicomposting is a great idea, especially if you want to keep the vermicomposting going really well outdoors.

      2. Hi, I have wondered for some time if two three layered worm farms one on top of the other would work, only problem that I can see is pulling it apart when the layers mount up?

  3. Hi Kate. Thanks for the feedback and disagreement is welcome around here! I am just applying the math that is applied to other forms of vermicomposting/vermiculture. If you go by surface area alone, 4-in PVC is just not enough surface area.
    However, you may be benefitting from better soil than I am in PA. And may I ask . . .are you using red wigglers?

    1. Your surface area argument only works in a contained environment. The tube is only intended to contain the concentrated food. The surface area is the WHOLE GARDEN. If property tilled and mulched, that is the area that will be worked.

      1. Hi Steven,
        Like I said, I’m open to evidence….and the arguments in the article aren’t only about surface area.
        If your soil is very loose, then yes, red wigglers may be able to come and go, but for folks with dense soil, red wigglers will not be able to go too far outside the tube.

        One way to find out is to pull up worms more than 6 inches around the worm tower. If they are red wigglers, then that goes against my theory.

        What I’m more open to is that subsurface worms like the garden variety earthworm are attracted to the organic matter in the tubes.

  4. Thanks Gena! I hope you keep stopping by! The blog is about to get a bit more busy as spring approaches, so stay tuned. And if you haven’t done so, please join my mailing list!

  5. Steve,
    I put 2 worm towers in my raised beds yesterday. My beds consist of composted cow manure and fresh rabbit manure. I do find worms in my beds naturally so I will try 2 beds for this season and see my results. So, the jury is still out but your thought is logical also. Thanks for the information.

    1. Thanks Ed! And your situation (where your garden is filled with stuff worms love, rather than just topsoil) is one where the worms will be able to come and go more freely. Check back in with your results!

  6. For the definitive information about vermiculture, Google Rhonda Sherman, NCSU. Rhonda travels the world as Extension Specialist, Solid Waste Management, Biological/Agricultural Engineering, North Carolina State University. She teaches backyard worm composting to municipal levels. She and I are Durham County Master Gardeners together. I have 2 worms bins because of her encouragement. One is home made, the other a stacking bin. Both are easy to harvest. Red wigglers are the diva’s of wormdom but are easy to care for.

  7. I built a huge worm tower with a 60 gallon barrel that is 23″ diameter. J drilled many 3/8″ holes in the bottom and about 1/3 up the sides. I buried it so that about 10″ are sticking out of the ground and then stacked 2 rows of firepit bricks around it. I got a lid that fits over the bricks so it just looks like a fire pit in the corner of my yard.

    I added kitchen waste to it all winter and I’m hoping when it thaws that worms get at it and either carry the waste away or break it down so that I can shovel it onto the garden.

    1. I just cant wrap my head around the harvesting of the finished product! Though I like the esthetics you described. On the other hand, the fact that only the top 12 inches will ever be “ready” makes it slightly easier to imagine. No it doesn’t, I’m still trying to get heavy wet material out of a hole below grade! That sounds too much like work. (!) At least your heart is in the right place, I do thank you for sharing. But I think I need an above ground stacked-tray set up, because if it isn’t easy to get at the finished product, I will fail miserably! And that can’t happen! I need that black gold!

      1. It takes about 10-15 minutes 1x in the fall to shovel out. Get the last bit out with a hoe. So far it haven’t been a problem. Biggest thing is that you have to do it and immediately rototill to keep the neighbours happy.

    2. My father in law said that his family used a post hole digger (the kind you twist) and they even added an extension so it would dig deeper. They put a trash can lid over the hole so no one would fall in & then just tossed in kitchen scraps until the hole eventually filled up… which was apparently a very long time, and then they would dig another hole.

      I assume that the deepest food wouldn’t be composted… perhaps some day anthropologists will be scratching their heads trying to figure out what they found. But it seemed to work well for them, and I imagine that it adds a good measure of organic matter to the soil at depths were it will be beneficial.

  8. Now that seems like the way to do a worm tower! The surface area issue isn’t really a factor anymore with a barrell that large. I think you’ll find that composting worms are only going to work the top 12 inches or so, but hopefully some nightcrawlers can still have a feast! Let me know how it works out after the thaw.

    1. I have just installed my worm tower in garden. It is 6 inch diameter and 2 feet tall. I could only dig about 12 inches deep to bury the pipe. I have been tilling the soil by shovel and see plenty of worms and my soil already seems dark abd rich. Previously, I just used a garbage can for compost and didnt have much success. I ended up burying some of its contents in my garden last fall. I wanted to see if this would work. For those who have seen success with this method, is it important to have a lot of holes somewhat close together? Inch apart, half inch?

    2. I also do carrot/apple juicing so thinking /wondering if worms will go for the scraps from this. I have learned worms dont like acidic items like citrus. But coffee is acidic. So I question what the difference would be.

      1. Kevin, Coffee has made my worm beds jump. I think the coffee is a dryer acidic so that may come into play as the worm skin is sensitive to the liquid in the other type acidic properties perhaps. I throw orange peelings into my general compost pile and it seems to decompose and I add it to my raised beds first. I also have movable rabbit pens over new raised beds catching the droppings to fill up the beds for future plantings. This along with cow manure seems to be a nice base for worms to thrive when introduced via my towers. Best Wishes !!!!!!!!!!

  9. Well I’m not sure what level it’s at now. I’ve not messed around with a below-grade in-ground setup like you have there. The worms WILL process material faster during the warmer temperatures, if that’s what you’re asking. 🙂

  10. I’m new to composting of any kind. I’ve heard that the freeze/thaw cycle can really help the process but I’ve never composted before so I don’t know.

    I’m hoping that the worms can break the waste down faster than I throw stuff in.

    Right now the bin is almost full but most of the deposits over winter went in as frozen lumps in the shape of a pail so I’m hoping when everything thaws there is a good drop in the level do there is room for more waste and also that worms get at it and reduce it even more.

  11. Ian,
    Well the composting comes to a near stand-still DURING the freezing times. But what freezing does is break down the cell walls of the organic matter which ends up helping it to break down more easily. This is why your hear of people freezing food waste before feeding it to the worms.
    But freezing conditions themselves are not ideal for vermicomposting. You’d rather have 75 degrees year-round rather than a continuous freeze-thaw cycle.

    1. Instead of freezing food waste, how about running it through a Vitamix blender (set to mushy) and then giving it to the worms?

      I’m trying to get several brand new raised beds going, horse manure, cardboard, straw/leaves for mulch, Ala Ruth Stout, but with some amendments.

      1. That would be fine, Mike! Just keep adding dry bedding when you’re making a slurry like that as the moisture is being released all at once vs slowly with the normal breakdown of the food.

  12. Ok so adding to the bin all winter is a good idea as long as I don’t run out of room.

    As said my only goal with this is waste reduction. I’m hoping that when the whole thing thaws the worms attack it and do most of the work for me.

    If the freezing of winter helps that along, great.

    With a bin my size how much waste will the worm be able to get rid of in 1 week? How much volume are you left with after the worms digest it. Eg if you have 10 lbs of waste how much castings would that make?

  13. I hate to be wishy-washy with the answer but that depends on the food. Most food is going to majority water weight, so most of the weight is going to vanish whether the worms eat it or not. If I were forced to guess, I would say you’d get a 5-10% castings yield.

    Now back to your worm tower . . with a diameter of 23 inches you are looking at a little less than 3 feet of surface area. Under the best conditions which, with an outside container, you are not always going to have, you can expect to accommodate 1 to 2.5 lbs daily. In reading through your comments, I am a little concerned that you are setting your worms up for a serious overfeeding – and overheating – when the thaw comes and that stuff really starts breaking down. I would probably find a different place for your food waste until you figure out how fast your worms are working.
    I’m really interested to see how this goes for you over the next few weeks. Let me know!

  14. If that’s the case I’ll hold off with adding worms till it composts some on it’s own first. If some worms from the soil want to get in they can go to town! I thought it would be slot more than 5-10% but hearing that makes me very happy because that means I won’t have to empty it as often or as quick.

  15. That’s probably a good idea. I was under the impression that you already had worms in it (which would have required some pretty good geothermal effect to keep them warm enough.)

  16. No I built it too late in the year last fall. Honestly I’m hoping that I don’t have to add worms and earthworms and other bugs take care of the waste for me.

  17. I’m not sure if there are naturally occurring compost worms where I live. No harm in giving it a few weeks to see.

  18. What other bugs, maggots, etc can I expect to come into the bin? And which of those are beneficial or harmful? Keeping in mind my ONLY goal is waste reduction, not harvesting compost.

    1. You can get different insects in your bed. I was swamped with black soldier fly larva last year but they turn the scraps into compost and at almost 40 % protein the chickens loved them and scattered the compost for me. I plan to attract the larva this year. I just added worms to my towers yesterday so I’m excited to see my results in a few weeks.

  19. What do you do or add to attract the larvae? Will they “show up” in Alberta Canada? If they do turn waste into compost that will still be easier to manage than the waste itself and I can throw it on the garden.

    1. I usually set some grain and let it spoil and the black soldier fly will find it. I am not sure if they are in Canada. YouTube can show you the best ways to attract and raise the larva. A never ending supply of protein for your chickens.

  20. Hi Ian,
    I can’t claim to be much of an expert of all the critters you may find in your bin, but I’ll say this. It’s often not the critters themselves that are of concern, but the conditions that attract them that could be an issue for you. They are an effect, not a cause, of problems.
    And you definitely don’t want a “gross” bin! If it’s gross to you, it will be gross to your worms! 🙂

  21. What Meant by gross was that if itvis crawling with bugs and maggots that want to help me reduce my kitchen waste that’s a good thing!

  22. Hello and thank you for your article.
    I am new to gardening in general and my boyfriend and I are looking to do this worm farm thing.
    I will not be making a worm tower of PVC after reading your article but your article doesn’t really suggest what to do instead.
    Are you saying worm towers and using worms for composting in general are a no-go?
    If not, what do you suggest and what kind of worms should be used?

    Thank you.

    Ashley from Alaska

    1. Ashley,
      Not sure about your temperatures since you are from Alaska. I have worm towers in my garden and worm beds. You can raise the worms and separate the castings and use them as a soil additive and or make a tea to water your plants. My towers are small and don’t take up too much space so I’m ok with them in my raised beds. I have a plastic 55 gallon (food grade) drum I cut the bottom out of and placed in my garden. Its a large bottomless worm tower and all my compostable waste goes in there along with worms from my bed to establish a colony (for lack of a better word). I will separate and move them when it looks like the compost has fallen or been processed. Worms are worth the effort for you garden if your climate can sustain them. Best of luck !!!!!!!!!!!

      1. Hi Ed. It looks like we have similar worm tower systems.

        How long can you add waste to it before you have to move it or empty it?

        After it thaws, how fast does the level drop?

        Are worms, bugs, maggots attracted to it?

        1. I have had to add larger pipe due to household size. I am running 6 pipes, 2 large and that along with my worm bins handles all suitable waste. My rescue dogs, cats, rabbit’s and chickens handle the rest. I use manure in my raised beds and that seems to be conducive to helping my worms thrive. I am volunteering at a reclaimed prison and we are adding vermicomposting to our list of things. Anyone local to NC can attend a vermicomposting conference at NCSU, to to their web site for further information.

  23. My bin is now thawed enough that I can force a metal rod through the waste. The level has dropped a bit I think just because of the thaw and that everything was frozen when I threw it in. The temp is still pretty cool at night but but during the day has been up to about 15C.

  24. Hi Ashley,
    By all means, worm composting is awesome! This entire site exists for it. My article references the extreme limitations you face when using 4-in PVC as an in-garden composting bin. You simply don’t have enough surface area available for your worms to process much food.
    Instead of this, I think you’re much better off having a worm bin separate from the garden, and applying the castings to your garden. You’ll end up with more castings that way.
    As for which worms to recommend, I would definitely say Red Wigglers or European Nightcrawlers. And I might even recommend Euros as you are in a colder than average climate. But there isn’t a huge difference in temperature tolerance between the two. But you’ll definitely need to move them indoors in the winter of have some method of keeping them warm enough outside.

  25. Hi Ian,
    As the temp warms, definitely keep an eye on that temperature. If you have as much nitrogen-rich stuff as I think you might, then you may have a hot composting process to go through before you can introduce those worms.

  26. Well I’m not sure if it’s the heat generated from the compost process or the warmer temperatures. I went to throw a pail full of kitchen waste in today and when I lifted the lid off the bin you could really feel the heat coming out of the bin. I painted the lid flat black before it warmed up thinking that it might help warm things up. Now that it is warmer do you think I can expect a fast and substantial drop in the level!

  27. Hi Ian,
    What I would imagine you have going on is conventional thermophyllic composting. This is not going to be good for your worms unless they have somewhere cooler to escape to.

  28. I live in Perth Australia where I constructed 2 towers using 0.5m lengths of 150mm pvc piping. They’re working fantastically. I get the carbon and nitrogen ratios right. Now thinking of expanding the system with scored 10 or so plastic Pails scored from a build site waste dump. No rodent or pest issue if the mix is right. Vegies are doing great!

    1. I’m with you Michael. I have the same size, quite a few of them and they’re great ! I use them for my excess scraps as I have 6 other worm farms/hungry bins, so there’s no reliance on these towers turning over the waste quickly. I have harvested casting from them though, so they are very clearly working and I haven’t added any worms to them.

  29. Hi Michael. Thanks for visiting! At 150mm (6-in) you do have a larger PVC width than is widely available here in the states. I am certainly willing to revisit my skepticism in light of all of these positive comments. But I am also noticing many success stories coming from people using larger than normal widths . . .which means greater than normal surface area.

  30. I am not able to locate red wigglers which seem to be the composting worm of choice.

    If I go to the bait shop and get the big night crawlers that are about 10″ long will they do anything good?

    1. Actually the worms at the bait shop where I live are Dew worms. Not sure if they are good for composting or not. The level hasent dropped much at all yet and it’s been warm for at least a month now. In June I am going to shovel it out into the garden and start over. All the contents will be under a foot of dirt so they won’t smell or be a pest problem. And I can keep adding new stuff to the bin. Unless I see a dramatic drop by then that is my plan.

  31. The level in my buried compost pit continues to drop. Good news is that you can hardly smell it when the lid is on! When you lift the lid….not quite the case!

    I added red wigglers to it a few weeks ago but I’m pretty sure it warmed up too much and that they all died. When you lift the lid there is a lot of heat in the bin. I’m going to shovel out the bin in a few weeks and start over.

  32. I disagree regarding towers. I have been using them for almost 3 years, never smell, and when I changed my bed over from winter to spring, spring to summer I find redworms in the soil a few feet from the towers. They are leaving the tower. Surface area argument seems irrelevant to me. Other bugs are in there digesting the scraps and then burrowing through the beds. I have to constantly fill my towers, I’ve never scooped them in 3 years.

    Chemicals/pathogens present in the soil are not necessarily up-taken by the plants and then consumed by you. I don’t know about this chemical you refer to in PVC. Do you know that it is drawn into the plant or are you assuming that? Either way, home grown food next to a pvc worm tower is much safer than food from the grocer, which has been sprayed with who knows what and been handled by who knows how many people.

    Worm towers aren’t the best way to vermicompost, just the easiest…. my two cents….

    1. I have had worm towers in my raised beds for 6 months. All contents get processed and no smell. I am having a hard time feeding my towers, worm beds, assorted farm animals all the scraps.

    2. If vinyl chloride is a class A carcinogen & cutting & drilling the polyvinyl chloride pipes is likely to cause more of it to leach into the soil, I certainly don’t want to put that next to garden plants I’m going to eat.

      I understand that we still don’t know how much is leached out, nor how much the plants absorb, but that isn’t very reassuring to me. Neither is guessing that it may not be as bad as chemicals that may have been sprayed on plants sold in grocery stores. That’s the type of thing I’m trying to get away from by growing my own. Fwiw, those chemicals have theoretically gone through the FDA testing/approval process for human consumption. The pvc pipes cut, drilled & inserted into our gardens haven’t gone through that testing process, flawed though some claim it may be.

      Bottom line for me, is that I would rather go through a little extra work if need be to avoid that risk.

      I like my father in law’s idea from years ago. His family dug holes with a post hole digger & they just tossed in the kitchen waste until it filled up & then dug another one. Seems like it would be just about as convenient without the risk.

  33. I shovelled out by bin yesterday and was kind of disappointed. The contents were not really composted and were just a smelly, slimy mess. We did our garden so when the landscaper dug out the spot for the garden I shovelled the contents of the bin into the empty hole. There they can take all the time they want to break down and there are no smells at all

    I will continue to add to my bin though and just empty it one or twice a year.

  34. If the next barrel full is the same I will just have to dig a hole in the garden for the bin contents and do trench composting.

  35. I have 6, 5 litre pails, with holes drilled all over – top, bottom and sides, around my gardens. I had previously just buried my kitchen scraps. Compost worms found their way in very quickly ( not put there by me) , and broke down their food in about 4 weeks – much faster than just burying. Sometimes I get a very wet mixture left at the bottom, I just remove it, put fresh scraps in, then put the wet goop back on top. Works very well. Worm farm or compost bins not suitable for us, due to space.

  36. In the fall I emptied my bin and tilled up the garden to work it in and also to get rid of the smell. I have been adding to the bin all winter and of course it is frozen solid.

    The change I did make about 1/2 way through summer was the lid. I got an old disc blade that let’s in bugs and allows for more air to enter than the old lid I had.

    With the new lid lots of flies get in and with that comes maggots. It looks like a horror movie when you open the lid but the good thing is that they eat the rotting food waste and there is no stink until you shovel it out. I’m hoping that this year with the new lid the maggots start sooner and I see a fast and substantial reduction in the level.

  37. Personally, I compost & mulch a lot, but I think these towers are way too plastic-like for a food system. Using pvc or car tyres in the garden is not a good idea at all.
    Actually, why not drop your humanure into these towers, or pee into them?

  38. Hi Steve,
    I’m a huge fan of worm hotels (as we call them) because they rely upon indigenous earth worms rather than compost worms. We call them ‘hotels’ because the worms call in for a feed and then head off into the soil, taking all their lovely castings off into the garden. I’ve installed garbage bin sized hotels in my own garden and tiny ones in the balcony gardens of friends and all of them work brilliantly. It’s best to add a few sheets of wet newspaper to the top occasionally to prevent smells and other insects. Other than that they are a ‘bottomless’ waste disposal system for organic matter that hugely improve the soil. I make them by drilling large holes into any lidded container. You can also move them around the garden easily. Just bury the bottom 30-60cm into the garden bed and add the soil you take out (hopefully with a few worms) to the top. I know conventional wisdom says that you shouldn’t feed them tomatoes, onion or citrus but I do and I’ve never had a problem. They eat everything.

    1. Thanks Meg for your comment. I intend on creating a few towers in my small, recently aquired, city garden with very poor soil. I have not yet seen any red wrigglers in my garden, only a couple of deep dwelling earthworms – not compost worms, if you understand what I mean. My question is whether the compost worms will appear, or if I will have to add some to get the process going? If I use old 5 litre buckets with lids, must I bury them completely, or just halfway? Thanks!

  39. Hi Emilia,
    Thanks for the comment!

    In case Meg doesn’t see your question, you would have to add composting worms as they do not exist naturally in the soil. And the soil surrounding the tower or bucket needs to be loose enough for a non-burrowing worm like a red wiggler or Euro to travel in. In the northeastern US, this is typically not the case.

    And I don’t know how deep a 5-litre bucket is, but composting worms typically work in the top 6-12 inches of their bedding/food mix.

    Good luck!

  40. It has warmed up quite a bit and the level has dropped so my 60 gallon barrel is now about 3/4 full. Of I course haven’t seen any bugs or worms yet but I’m hoping that that changes soon and that the level drops fast. There may be some worms deeper in the bin but I’m not going to dig to find out. The only time I plan on digging is when I empty it and I hope I don’t have to do that till fall.

  41. Hello all , i have 7 holes digged 3 feet deep and 10 inch pipes has holes around with just 20 cms of the top of the soil without holes to hold a 10inch cap. We have 10 people in our home so the kitchen waste is quite big.We use 1 pit a day so all 7 pipes get fed weekly once.And this has been done 15 months and never ever smells. I stay in tropical region thats indonesia.The pipes seems to be bit empty every week so its ready to take waste once in a week easily.I am planning to replace the PVC with tin pipes with holes making it bit better than using PVC. we have rains 6 months around and i fear PVC polluting the land.

    1. I would worry more about the heat of the new tin pipe. I use PVC in my garden and fields. I recently got discarded water line ends just by stopping and talking to a line crew supervisor. Good Luck !

    2. Hi Pawan, I also have 10 people in my household and live in tropical Hawai’i. I’m starting with just one 5 gallon bucket with 3/4” holes all over the sides and bottom. It’s buried about 1.5 feet deep with 5” above ground. In what ratios do you add your kitchen waste with your carbon? What is your carbon source? My worry is the smell. Do you cover the top of the pipe and cap with straw or mulch, or is it exposed to the sun? I’m afraid it will heat up too much here – 85 degrees F days most of the year. Finally, do you think I can get away with 4 towers, feeding one every other day? Thank you,

  42. I have not emptied my bin since last fall. I added to it all winter and it is now summer and it’s still about 3/4 full. I add ALL kitchen waste to it including meat, dairy, and citrus. At this rate I’m thinking that I will easily add to it until fall when I will shovel it out again and start adding to it over winter. Last year that’s what I did and after rototilling you could not recognize any of the contents by spring time.

    This spring I also got an earth machine and plan on spreading it’s contents which are mainly grass clippings and shredded newspapers.

    With collecting the waste for a full year and then rototilling it into the garden before fall it seems to make beautiful soil by the next spring.

  43. I believe the soil pipe model does work, because I worked the project in the other direction.
    I sunk a soil pipe with drainage holes drilled in, 12 inches deep and filled with scraps as you do and waited four weeks in spring for composting worms to come to the feast in the pipe.
    That gathered my first 200 worms or so that I started my first worm farm with.
    True, composting worms do not burrow, but they do move around int the first 12 inches of the soil layer (of a no-dig bed), so they could in theory enter, feed, exit and poop near your heirloom tomatoes and then return for another feed.

  44. This year was much better than last year with my 60gallon worm tower.

    I shovelled it out about a month ago and as before it smelled really bad. Being a full year since it has been emptied though has given it much more time to break down and be easier to work with. Most of it was the consistency of mud.

    I emptied the bin and also my Earth Machine composter which was full of grass clippings and shredded newspaper. I spread both of those on the garden then spread 2 square bales of organic barley straw on top.

    After doing that I got the garden rototilled which buried most of the straw.

    The awful stink was gone within 2 days. Now the straw and compost has until next spring to neutralize and be further broken down by earth worms. I plan on getting the garden worked up again in the spring time before planting.

  45. I have a standard green worm bin on my balcony and feed my red wrigglers kitchen scraps. I also shred toilet paper tubes and paid bills to use as bedding. I don’t put coffee grounds or citrus peels in.

    I’ve only had one winter freeze in Vancouver, BC, and thought I’d lost them, but the eggs survived and I got a lot of baby worms in the spring.

    I saw a tiny house video on YouTube where they had a tube outside of a kitchen window to the worm bin below. The unused cup tube from my 5 gal. camping water barrel looks like a good tube to use for feeding.


    1. Having seen the mass extinction of a whole population of worms from a closed system, I vowed I would only ever use systems where worms could migrate away and return back in according to how fit for habitation the system was.

      1. Good policy, I have worm Towers in all my raises beds. I use a combination of cow, rabbit, chicken manure and wheat straw as a fill and worms seem to like it.

        1. Yes, I use a bottomless system now directly onto beds where I want a high nutrient level. The good stuff is migrated or leaches out into the bed and is taken up by nearby plants strategically planted and worms are free to be in the tower or leave into the upper layers of the no-dig bed.
          Composting worms will happily remain in the top few inches of the soil so long as there is enough decomposing matter there to live and eat in and they are attracted back into the bottomless worm tower as it provides good eating and shelter. If it gets too wet, smelly or too dry, they are free to escape.

  46. how about using sonotubes, those cardboard tubes for pouring concrete..they are ecofriendly material, designed to last years in soil, large diameter and easily drilled for holes…12 inch diameter 4-5 ft long inexpensive

    1. That is a great idea Jim! Solves two of the problems right away.
      How would you go about getting one of those??

    2. Does anyone know what sonotubes are made of? Online information is vague (“fiber and adhesives”) so I’m wondering if they’d be safe to use in a vegetable garden. Particularly with holes in them.

  47. Home Depot or similar type store has them. They may even have a squashed one for free or cheep! Nice thing about that would be when it’s full just cover it with dirt and dig a new hole! That sounds like something I wish I would have come up with

  48. Hi Steve great forum, here in Brisbane Queensland I have many towers spread throughout the garden.Have placed them near the front door and I am still happily married lol The smelly wet mess mentioned beforehand I have never experienced and have found that if correct compost practices are carried out ie no meat ,try and keep a little moist and if possible try the carbon nitrogen ratio as best you can then you will do ok.I still marvel where all the waste goes.Kind regards to all our American friends

  49. I am experimenting with two Home Depot Buckets in a 4×8 Raised Bed… I have one bucked I put food in. Then my plan is to start putting food in the other one, and see if the Works will move to the other one. Then I will clean out the Castings in the other, and do the reverse.

    1. I would put the 2nd bucket as close to the 1st as possible and make a food trail (with ample coffee grounds), to encourage the worms in the general direction you want them to go. Best Wishes!

    2. We often come up with ideas like the worm tower because we want to feel we are doing something to help what nature already provides. The best surface area would be the whole of the vegetable bed and while it is true that composting worms are not soil dwellers, they do gather and thrive in the top layer of rotting compost if you top dress with compost or just chop and drop vegetation to decompose where it lies.
      Just dropping your kitchen waste, prunings and weeded plants where the growing of vegetables is to take place dispenses with anaerobic rotting, deals with the surface area problem and attracts more composting worms per volume of decomposing vegetation.
      The only problem with this is – we no longer have a use for that soil pipe, drill, saw, garage, spare weekend etc.

    3. I would add to them one at a time. When 1 is full and the level stops dropping put the lid on and leave it. Then add to the 2nd one. By the tine the second one is full you should be able to shovel out the first one and start over. I wish I had room on my yard for 2 bins like that. Instead I shovel my 1 60 gallon bin out in the fall and it has until the following spring to finish. After a fall and spring rototilling you can’t recognize any of the contents.

  50. This summer I’ve had a few days where the bin has smelled really bad. On those days u tore up some newspapers and cardboard which really helped the smell. The level continues to drop even with the extra paper. It actually seems to be dropping faster than it did last year so I’m going to keep doing that. In the winter I might even put a few layers of paper in as I fill it. You can’t smell it in winter but it might help it even more when it melts.

  51. I don’t worry about it too much. This is the 3rd year I’ve had it now. With emptying it in the fall and working it into the garden it gives it all winter and the following spring until may to neutralize. By then it is just dirt and none of the contents are recognizable. I started this thing purely as a way to eliminate kitchen waste-it works!

  52. Hi Steve, I live in rural New South Wales, Australia, and have recently installed 3 PVC towers in my newly formed garden beds. Do you have any ideas as to how to keep the towers cool in our sometimes 40º summers? Is it necessary to keep the towers cool or do the worms just bury themselves deeper into the soil? I am using composting worms at present but after reading all the articles, not sure if I should be using the red earth worms?

    1. Hi Irene, I’m just learning about worm towers but I’ve lived all over NSW and I’ve had various kinds of worm farms, compost bins, no-dig gardens and other combinations. The temperature problem is real but in a garden bed the worms will move out and bury themselves deeper, and (maybe) come back when conditions improve, especially if you can keep the garden moist.
      I’m in Nowra now, downsizing to patio gardens so the temperature is something I have to deal with. This year I’ve built wicking beds in broccoli boxes for herbs and seedlings and I have worm towers in them made from 300-500 mm lengths of 100 mm PVC pipe. All I can say for sure is that the worms (red wrigglers from my compost bin) are growing and multiplying. The wicking box does moderate the temperature and I’ve left them in the sun on the hottest days we’ve had this January.

      1. https://www.kookaburrawormfarms.com.au/shop/worm-eggs/little-rotter-garden-bed-worm-farm-single-pack/

        I’m experimenting with an above ground vermicomposting system based on the link above. The claim is that it will enhance a 10 square meter area of ground, and the worms will level the above ground material into the ground. Composting worms and native worms feed, then deposit the digested material outside the container. At least that’s the claim from the website. “Worms have a natural tendency to level out the soil and will therefore empty out a bucket sitting on top of the soil, but will fill a tower buried under the soil.”. Seems like folks who have posted above have had luck with towers not filling up, but that wasn’t my experience with a 4″ pipe.

  53. So, you saw a youtube video about a cool idea, then asked an “expert” with no experience with this particular idea who laughed it off, so you’re sure its the “wrong product”. I too was skeptical of this idea when i saw it on another site, but the enthusiastic endorsements and photographic evidence of more than a few people convinced me it must be legit. In response to some of the comments, I think the idea is that you install it right in your garden bed and don’t “harvest” any castings because they are already where they should be. People have had success throwing nightcrawlers from the bait shop or red wigglers in at the beginning, and others have just relied on the worms already present in their garden beds. Also, I didn’t get the impression the towers I saw were buried 12-18 inches deep, more like 2-6 inches deep so the worms could come in through the bottom, not a few small holes. The square towers made of wood ( the ones i’m thinking of were like 8″ square, 2′ tall) seemed most successful for whatever reason – really impressive results.

    1. Hi Rob, my skepticism – which isn’t me saying it doesn’t work for sure or that it can’t be good for your garden – isn’t just based on a single source, although it’s understandable you might think that based on how I wrote the article. It’s mostly based on the assumptions we make about A) how many worms you can fit in a given area, B) how much those worms can process in terms of their own body weight and C) how composting worms move through soil, especially the kind we have in the Northeast US. If A, B, and C are all true, then a 4-in diameter PVC worm tower is not processing much food at all. The square towers you’re mentioning have a significantly higher surface area.

      As you can see from the other replies, plenty of folks disagree!

  54. I had good luck with Worm Towers this year, but my approach was different. I used Two Home Depot Buckets and Lids w/Brick to hold lid on. Drilled them out buried them where the buckets were about 90% covered, put one on each side of my 4′ x 8″ Raised bed… I would put scraps on one side, then two weeks later, I would put scraps on the other side. The worms would travel from one side of my bed to the other. Now the season is ending, i am pulling them out, harvesting the compost, putting my worms back in my Worm Farm 360 for the winter months. Next year I will do this again.

  55. Larger (5 gallon+) covered worm towers make great redworm traps. Position them around horse farms baited with a dozen rotten apples each, mix in shredded cardboard. Do this in the Feb-Mar. time-frame & plan on harvest early to mid-May. Spring rains enhance worm mobility and the rotten apple aroma attracts the worms.

  56. Hi Steve,
    Thanks for raising this question. The range of opinions in the comments shows that local conditions are extremely important. In coastal NSW high temperatures are a more serious problem, but my limited experience is that in these conditions worm towers will grow red wriggler worms successfully. I can’t yet comment on yield of worm casts or worm wee, but my herbs are thriving.

  57. Agree with the points raised in original article.

    Firstly, from a vegetable garden perspective, I don’t need compost/worms much deeper than 7 or 8 inches.
    Secondly, I DO need activity across the whole surface of my garden, not just a few inches around a pipe stuck in the ground, and this system simply cannot provide that. My red-wrigglers stay put (I use a 200+ litre upturned bin type of vermicomposting system), and gravity is only going to take liquids from the tower system in one direction . . .
    Thirdly, I need as system whereby I can harvest the finished compost / worm casting mix for targeted use, and again, this system doesn’t provide that flexibility. I can imagine how difficult it would be trying to dig down through in-process material to get to the finished product at the bottom of the tower, then withdrawing the finished product while a) protecting my back from strain and b) leaving the in-process materials in the tower.

  58. Hi, I’ll be trying this system a 1.80m x 1m urban garden in Mexico City. As I renewed my garden this spring, I noticed 4″ to 5″ earthworms feasting on the left over scraps all over the garden. I put 3 4″ pvc pipes and added red wigglers, and also targeting to atract my native earthworms. I let you guys know about my results by fall!

    1. I have worm towers in my raised beds but don’t know how to judge if they’ve made a difference. Thanks for sharing!

      1. Hi Charlie, It’s been 2 week’s since I installed my 3 worm towers and believe I see progress. I spent my sunday installing a droplet irrigation system and a low fence to keep my cats from hunting and bringing worms indoors. While digging, I noticed more earthworms than usual, (perhaps because of Ive been pouring worm tea into the soil to encourage bacteria devolopement) and red wigglers already integrated into the garden. I also emptied my 3 worm towers, and found dozens of baby worms in them, as well as adults inside, which happened to look quite happy in there. While cleaning up one of the towers, to introduce new scraps, I noticed a panicking red wiggler escaping through one of the holes on the pipe, into the garden. Took a few pics as evidence that they do come in and out the pipe and burrow into the garden. However, despite the good progress of my worm colony (according to my limited criterion) I also, have no evidence yet, of it improving the garden.

  59. After a few years of using my 60gallon barrel worm tower I’m going to try something different this year.

    I going to put my earth machine composter over top of the buried barrel and add both kitchen waste and lawn clippings to it until fall. I’ll see how it works and the descide what to do for the following year.

  60. I have worm “towers”. That is to say I have 5 gallon buckets with lids and plenty of holes drilled around. Ive found the key is a feeding rotation. My garden in only 540 sq feet. I use 5 buckets arranged like 5 is on playing dice. I started with the center and fed until the bucket was nearly full of castings. ( about 6 weeks) then stopped leaving the contents and began to feed from one of the corners. Fed until nearly full of castings the stopped moving on to the next bucket..and so on( you get the idea). Finally when the rotation gets back to the beginning, the center bucket, I sift the contents and use it in my potting mix or compost tea.

    My garden has done better than ever since i started this. Its a slow process, but worth the wait.

    Starter mix for the bucket

    Bottom 2″ castings from previous buckets, manure or potting mix without fertilizer.

    Next 3″ yard waste. I use fallen leaves or forest litter. ( my back door is 15 feet away from deep woods my garden is in the front yard)

    Next 6″ of comparables a decent mix of brown an green. My little wormies seem to prefer a 6:4 ratio green to brown.

    Add 1 quart water
    Top off with 1 disc of card board wet then replace lid.

    To feed
    Add about 2 quarts compost once a week UNDER THE CARDBOARD.

    This is merely my experience and what works for me. I hope it can help some else….WARNING: worm towers and gardening with worm towers is addicting.

  61. I left out the buckets are buried to the lid. They resemble little blue manhole covers. This is important. I’ve seen others try buckets and only bury them half way. With less success. Not sure why.

  62. Stephan, I appreciate the fact that you are letting your peers comment on this.

    However, the video of your worm tower shows the holes in your worm tower. They appear to be way to small. I just stuck one 4” x 18” in my raised garden bed with 5/8” holes in it. I’ll be putting in 3 more tomorrow. I’m putting them in at different depths (with the holes in the ground.) And I’ll be feeding them different foods, i.e., pasta, breads, etc. one with garden leaves etc., one with veggies and fruit waste and one with compost (from the landfill) and peat moss etc. BTW, I live in SoCal so it never freezes here. I’ll get back to this site in a couple months and let everyone know what I learned.

    1. Thanks Mark! If my memory serves, I think my holes were 3/8 inch which should certainly be wide enough for worms to come and go. Looking forward to your updates….

  63. My urban garden is looking nice, but still not sure it’s because of my worm towers. What I have noticed since I installed them and water worm casting’s tea was a reduction on my snail and slug populations.

  64. I drilled 1/2″ holes (bottom and sides) in a 10 gallon tote, and buried it a couple of inches. I only add kitchen scraps and water every morning. I would like to know how far the earthworms will carry the compost. It has been half full (about 6″) for a while. The bottom material continues to decompose and is full of worms. we live in Zone 10/ So Calif.

    1. I’ve been using my 60 gallon worm pit for 5 years now. Last fall I shoveled it out as other years. This winter I started adding shredded paper between layers and now the bin is so full I can’t close the lid all the way. I thought the paper would be a good way to keep the smell down which in the past was bad.

      When it warms up I’m hoping the level drops.

      I also have an Earth Machine that is used for grass clippings in the summer. This fall I filled it with coffee grinds and wood ash from the fire pit. If the level drops enough I’ll just throw grass clippings on top. If not I’ll have to spread on the garden in the spring time. Right now the bin is full and it’s frozen rock solid. How much do you think the level of the ashes/coffee grinds will drop?

  65. I’m afraid I found this too late, and the concerns about bugs are definitely ringing true for me.

    I haven’t had a problem with pill bugs, earwigs, or slugs in the past — but I definitely do this year. The worm towers seem to have attracted them and given them an ideal breeding ground.

    Unfortunately they’ve now also infested the rest of my garden, and they’re chewing their way through my seedlings.


  66. I looked into this and found the exact same dilemma. Worms that eat compost don’t burrow around outside the bin and vice versa. I remember seeing a video where a woman said a certain kind of worm was best. They’d come on in and process the compost then head outside to drop their castings, then return again for compost. The trouble is that I cannot remember which kind of worm she had said and I cannot find that video.
    But I wonder if this may be even worse than doing nothing. Perhaps all the surrounding worms that would be working your entire garden will now just hang around in or an inch or so from your tower.
    If you’re claiming your getting good results from the work tower then for the love of God, tell us what kind of worm your using and what radius around the tower do you see a good worm population.

    1. You’re absolutely right Joe!
      What I think actually happens here is that non-composting worms are attracted to the organic matter in the tubes. THOSE kind of worms are able to come and go into soil much more freely than composting worms are.

      1. Hi Steve:
        I just found your blog on worm towers. It is really helpful with all the comments. My question: what do you do with the “mud” that collects at the bottom of the bucket? Do you remove it or just keep adding materials in it.
        I have 5 gallon buckets with holes on the sides & bottom in a raised garden. I believe I have earthworms & maybe red wigglers. I add shredded material to help with the moisture.
        Someone mentioned that I should vermacast at the bottom of the bucket; however for about 6!months now only mud.

  67. I live in Melbourne Victoria. I have installed a worm tower in each of the 4 raised beds in last 2 months. I have hogulkulture beds with 10 to 12″ top soil. I have used 15 liter buckets and drilled 16 mms holes in the bottom and sides ,up to 6″ from the bottom. I have burried the buckets 10″ into the dirt. I have placed the lids on the buckets with 3″ holes in the lids. The holes are covered by a flyscreen mesh to get rid of the smell if it does occur. I have populated 2 towers. My issue is that the first tower has white flying/ jumping insects which I presume are springtails. As soon as I open the lids, they jump out and spread all over my garden bed. I am scared that these insects will attack the veggies that I grow in the bed. Tomorrow is the first day of spring. Any ideas

  68. I think you may be missing the point of the pipe-style worm tower. If I had a garden, I would have a number of options for composting. As someone with a small patio, I have limited choices.

    I had a full-scale worm farm once, but I had trouble with rats. Also, it’s not an attractive thing to have on a patio which is also an entertaining space. And finally, I could see it would eventually produce far more compost than I could ever possibly use on my potted plants.

    I’ve moved to another apartment, and now have space for a (small) raised bed and am enjoying growing a few vegetables. I hate throwing away organic waste, but I don’t have room for a worm farm (plus see issues above). People have suggested a Bokashi bin, but once it’s full, you need to bury the waste in the garden – and I don’t have one, or know anyone with one.

    So I come back to the idea of putting a small tower in the raised bed. It may not be perfect, but the question is – is it better than nothing, which is my only other option as far as I can see? And how small can it be?

  69. Ok, old article, I know… but…

    And apologies if this has been said above somewhere.

    I have several of these installed in my yard. I chop up weeds for them when I don’t have food scraps. Usually everything gets run through my old daggy food processor first with some coco peat and then into the tubes. All has worked well!

    I live in a very arid hot area of Australia, an above ground worm farm would cook, even in deep shade.

    I did not use composting worms at all – that solves several problems at once, especially the surface area issue.

    Our regular earthworms eat the surface of vegetable scraps that have begun to decompose, all that microbe and enzyme and fungi rich slimy surface… they are happy and fed, and the gardens have reaped the benefit.

    The other benefit of existing worms is that when you don’t have scraps, they move out of the tower and go shift around in the beds.

    Everything has come on leaps and bounds, especially as I teamed up ollas and worm towers, ensuring adequate moisture for worms and plants in my thirsty soils.

    As regards inside vs outside of pipe, well, to my knowledge, pvc is extruded into it’s pipe shape and is a totally homegenous material throughout.

    I’m sure there are many worse things coming into our gardens – which doesn’t mean we shouldn’t try and reduce it, of course. I would be more concerned about above ground plastics in other worm farms degrading and outgassing in my extreme climate.

    There are pros and cons to everything, but for me, this has worked beautifully and the worm population has increased in other areas of the garden as well.

    Happy gardening, All!

  70. I don’t know! To me, life is one grand experiment. I have 4 raised garden beds. About 100 sq ft I’d guess. I love my 4 worm towers. Pulled a carrot out today and there was some kind of earthworm attached. I don’t care what species it is. I’d guess it was a red worm? As I began “I don’t know” and furthermore, I don’t care. Best Buzz

  71. I was thinking of building a vertical worm farm out of a small wheelie bin. I think a 120 Litre.
    The surface area is wider than a tube and the waste should pass through to the bottom where i will have a tap and draw to remove the waste compost.Has anyone done this would like to get some ideas for my project.

    1. Something I would like to try this fall is to dig a few holes in the garden with a post hole digger. They will freeze and should hold their form over winter and I could add kitchen waste to them over winter. Then what I’d normally be transferring from the pit to the garden would be placed there directly. Then over summer I could use the pit but because of a winters worth of waste in the holes it would be less to shovel out in the fall.

  72. I both agree and disagree with your article.

    I too believe that worm towers are well intentioned but don’t quite work as theorized.

    I have made many homemade towers.

    ALL of them have fruits and vegetables and flowers growing AMAZINGLY.

    So, in my first hand experience, something about worm towers works. Everything planted in the towers is doing really well.

    AND I don’t believe that the food scraps in the feeding tube are actually feeding the worms.

    Composting worms don’t burrow, so it seems like they are just feeding from the organic material in the planter-not from the food waste in the pipe.

    So, it seems like the only way for the feeding tube to work as a composting system is if it is filled to the top with bedding and food waste, for the worms to come and go – in which case it won’t serve as a place you can put your spare food scraps.

    But how I do it, which is to put scraps in the tube when I have them, so the scraps are probably a foot below the surface of the soil, I can see that the scraps don’t get eaten.

    So, in essence, the tube is just a composting in place tube. It will eventually decompose and compost.

    But I don’t think the worms use the feeding tube.

    And 4 inches is too narrow to harvest castings or anything else.

    BUT, the worm towers are doing awesome and everything growing in it is doing great, so it’s doing something.

    I suspect that worms are in the top 6 layers doing what worms do, eating the soil and compost and burrowing and leaving their castings and the plants love it.

    Every time I dig in those planters I uncover a worm so I know they’re in there.

    But I think the feeding tube is extra and unnecessary. I think just adding worms to the planter has the same effect.

  73. What I’m concerned about with the worm towers is that it was suggested that PVC pipe be used. I am concerned because it is poisonous. What type of plastic pipe do I use instead? I have heavy clay soil so I’m trying to improve it by digging deep. Don’t have to worry about the cold because I live in Australia.

  74. Not sure if anyone will read this so late in the discussion, but I would like to add my 2 bobs worth (Aussie colloquialism) into the discussion. I was under the impression that a worm tower was an in ground composting system aided by worms, not a worm farm system, therefore the concept of harvesting castings etc. was never in the plan. Rather than having the human input of collecting the compost when it is finished and taking it to your heirloom tomatoes, the tomatoes or any plant’s roots seek out the nutrients of the composted waste. As far as the heat aspect goes, just like in my compost bin, the worms go deeper into the ground until such time as the temperature cools. Also, as it is placed in the garden surrounded by plants, these will shade the tower, keeping the temperature down. Just think COMPOST and not worm farm and your thought patterns will shift.

    1. I have a stackable worm bin that I harvest castings from and use for my plants. I also have a 5 gallon bucket with a lid that I throw things into like citrus (that composting worms don’t like) and surplus food waste that isn’t ready to go into the worm bin, since you don’t want to over feed your worms. If the 5 gallon bucket ever fills up, I dig a hole in a flower bed, near the base of a tree, etc and toss it in. The thing about composting is to keep it simple so you continue doing it.

  75. I have used 6 worm towers in my garden for approximately 8 years. While I agree they are not green (have learnt a lot in the last few years) they have worked very very well. Never a smell and I don’t use worm farm worms in them, the worms just arrive naturally from the garden and very efficiently get rid of waste. I do prefer the square larger ones now on the market and will be investing in some more. I think they are a great option for someone that doesn’t want to compost

    1. I believe you, but why the towers instead of just putting waste right into the soil? (I’m still trying to figure all of this out!)

      1. Practical answer for me is so that rats and other animals wont have access. I put meat, bokashi and cooked food without worry

  76. I came here trying to make sense of the worm tower concept (since you can just bury your scraps and be done with it). I learned a lot and as a bonus, got a day’s worth of laughter from the patchouli and graveyard comments. Ya got jokes, for sure!

  77. Steve hi, I am in Hillcrest, Durban,Natal SouthAfrica lat 29.8 long 30.0. Thank you for your maths. Interesting. We all have swimming pools ,hence use chlorinating pool floaters. One per mth. We have a number of standard 400mm high plant tubs around. (We are metricated ,hence withit not retro),.To ease watering the tubs and forgetting and loosing plants due to evaporation and hrowing away these floaters I cane up with the idea of a water reservoir and earth worms tower (just use standard worms dug up from wet. patches etc ,nothing fancy. Drill the top half of the tower, use bottom half of a shampoo bottle to close the inner tower hole,fits snug, Drill 4 holes high in the floater section,in the recesses there for a capillary medium,hessian rope etc. Drill one mire fir a plastic filler pipe ex drip filter garden system ,cable tie the top end verticle parallel to the tower. The floater comes with a screw on top ,just trim the inner side stops of the cap. Plant the reservoir,earthworm tower deep in your tub ,fill with soul halfway arrange your capillary ropes etc . Refill and plant your plants, paint cap green etc to blend in to tub. Use grass cuttings, leaves kitchen scraps etc. Maths aside, it does work . Using them for a couple of years now. Strawberries , flowering shrubs ,herbs etc. Good for hot balconies.

  78. Hi Steve, thanks for your informative article. I create these Worm Compost Towers, decorate and sell them at a local nursery. I know they are not perfect due to the pvc pipe and other reasons you pointed out, however, in my experiece they do work well for small gardens. I decided to try them as I dislike worms and the idea of cleaning outbthe worm farms. My dad has many successful worm farms so he was my original tester of the Worm Tower, which got his seal of approval. He especially liked the esthetics of the Tower as its was hand painted by me and sits as a beautifulvpiece if art in his garden. Whereas his worm farms are hidden down the back behind his shed. I put one in my garden 2 years ago next to my Bird of Paradise which never realky took off or flowered. I used Red Wrigglers to start the Tower off and they have thrived. The compost doesnt smell evenvin Australian summer as it is planted in shade (recommended). Since having the WCTower my Birds of Paradise are taking over the garden and are now producing the most beautiful flowers. So, Im taking your information on board and will reasearch other options to deal with the pvc issue. My drive is to make composting attractive to city dwellers, by way of making the WCTower attractive, inconspicuous and easy.

    Again, thanks for your information as I am always learning and trying to do my best.

  79. * sorry for typos. Im with a dodgy phone screen and cant arrow up to check before sending. Thats my excuse and Im sticking to it 😁

  80. I put a gallon container with holes on my raised bed, dug about 12 inches, put a pot as cover, put some worms and feed kitchen scraps weekly. Works fine, my raised beds are mostly manure and compost so worms eat them too. I notice castings are everywhere in the bed esp mulched parts and have castings too in the gallon container. Other critters take on the scraps, bsf, etc. Now im thinking of using a bigger, rectangular container like a trench vermicompost. But the current setup works.

  81. I came across your article while I was researching the concept of worm towers, as well as various alternatives such as other forms of vermiculture, worm bins, worm bags, etc.
    You made a number of points that make sense, including:
    1. If I intended to build a container for aerobic composting, the kind where you have airflow through the whole pile and it heats up to 160° and kills all the pathogens, then I agree that a 4″ diameter cylinder would be a ridiculous design and would likely lead to the outcome you described, of a “stinky tube of garbage.”
    2. Also, you make an excellent point about red worms being surface dwellers and not migrating through one’s garden, leaving worm castings behind them as they go.
    3. I, too, have wondered about the wisdom of using PVC for garden projects, and have decided not to use it. I agree that PVC is not “green.”
    However, there are ample testimonies from people who have made worm towers and claim they work as advertised. On the assumption that they can’t all be just lying, I decided to try and reconcile their points of view and yours. Here is what I have come up with, and I would be interested in your thoughts.
    First of all, you make it sound as if the kitchen scraps need to turn into compost before the red worms will start munching on it. However, everything I read tells me that the red worms eat the kitchen scraps. Am I wrong?
    If that is true, if you introduced kitchen scraps to your worm, let’s say “system” (whether it’s a tower or a bin or a bag or whatever), at the same rate the worms are consuming it, then you would never have a “stinky tube of garbage,” but whatever is left behind after the worms are finished with it. I concede that “compost” might not be the correct term for these leftovers, but the term “worm composting” has entered the conversation so I will continue to use it, even if it is a misnomer.
    People who have built them suggest that the red worms migrate upward through the layers of kitchen scraps added over time, so presumably the “surface” the worms experience inside the tower is higher than the surface of the ground outside the tower. No articles about worm towers that I have red explains what happens when the worms get all the way to the top and that is their “surface” but presumably there the process stops. Most of the articles imply that the organic matter is reduced in volume as the worms digest it and eliminate it. If the process were slow enough then I suppose it could last a whole gardening season, after which one could the dump out the contents on one’s garden, as if it were a bin or a bag or whatever, and start over again next season (with new worms, I presume).
    Secondly, I accept your proposition that proponents of worm towers who claim that the worms distribute their castings throughout the garden by exiting the holes drilled in the underground portion of the tower are wrong about this. However, they don’t have be lying, they might just be mistaken, misattributing what they observe as being caused by the red worms. In other words, I hypothesize that in a garden bed with a healthy earthworm population, these earthworms will enter the underground portion of the tower through the drilled holes, find the castings left behind by the red worms to their liking, and exit again back to the main garden bed leaving behind their own “re-castings” in the soil of the garden bed. If I’m right, then no matter what structure you use for your vermiculture, it amounts to red worms eating organic matter, and a good population of earthworms in your garden bed will be a “force multiplier” which improves the benefit of your red worm’s castings. If so, if you do not have a good population of earthworms in your garden, you need to figure out a way to introduce them. This would be a whole other topic, but one that should be addressed whatever worm “system” you adopt for the consumption of organic matter.
    Now everything I’ve said is theoretical since I have never tried any worm system. I live in a rented apartment in a suburban environment, but last year my landlords agreed to let me have some garden space, and to help me be as organic as possible under the circumstances (i.e., no application of any chemicals in that part of the yard, while I keep the weeds in check). This year they have agreed to my experimenting with vermiculture, type chosen by me, with the proviso that if it turns into a ‘stinky tube of garbage” I will immediately cease and desist and remove the cause of offense. So I’m motivated to find a successful way to do it; plus I really want to get out of the cycle of putting food waste in the landfill. I’ve decided to try something that also gets around the PVC problem–using food-grade buckets (BPA-free High Density PolyEthylene, which is #2 plastic to most of us). This will necessitate a slightly different architecture than a tower.
    If you’re interested, I can tell you about it and keep you updated on the outcome. Of course, it goes without saying that if it fails (especially because of the objections you raised), I will own up to it (and eat a healthy serving if crow, with worms in it).

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