My Big Fat Worm Bin

These worms are fat and happy

Some of you may remember that Earth Goddess Nancy Klehm taught a vermicomposting class at our house in October. Some of you reading this may have even attended!

That day, Nancy and the class foraged and gathered materials to fill a bin and worked together to chop, moisten and prep the materials. The materials included our own kitchen scraps, farmers market trimmings, cardboard and newspaper gathered from neighborhood recycling bins, chunks of our infamous prickly pear cactus, a “nitrogen contribution” from one of the more intrepid class members, some well aged humanure compost and some of the aged cat compost from our kitty litter compost barrel. (More on that later.) We didn’t have our final worm bin built at that time, so the materials were layered like a lasagne in a 50 gallon drum. When introduced the worms from our sad little kitchen bin into this pile of goodness, the worms thought they had landed in nirvana.

Since then, Erik has built a giant wooden bin for us following Nancy’s plans. It’s a simple thing, very like a toy chest. Nancy’s plans called for it to be 4 feet long, but Erik built the chest 5 feet long because he was working with 10 foot boards (less waste that way, you see). The result is a long pine box that looks disturbingly like a coffin! But that’s okay. Really, what better than a pine box full of worms staring us in the face to remind us all that we have to seize the day? 

Why do we have a coffin on our back porch, you ask?
The inside view, proving it is not a coffin. We’re going to decorate this somehow–which might help, or it might just look like we have a decorated coffin on our back porch. Right now the process is stalled because we are bickering over which pretentious Latin motto to paint on the side.

I transferred all the contents into the coffin box. What was interesting about Nancy’s mix is that it is much more like an active compost pile than the traditional newspaper shreds + scraps that make up a typical worm bin. The materials had heated up while sitting. Heat isn’t good for worms–they like to occupy cool compost piles–but I figured in a box of that size they could find cool pockets and edges to hang out in until it cooled off.  And that’s exactly what they did. There weren’t so many of them to begin with, and they were happy to hang out on the top layer until the rest cooled.

Since then, a wormy miracle has taken place. First, given the space and resources, they’ve started breeding like crazy. That’s to be expected. More interestingly, they’ve grown. The worms are getting super big and fat. I figure they’re like goldfish, adapting to fit their space. I think they really like the diversity of materials they’re living with, both in terms of habitat and nutrients.

The surface of the bin as of today. You’ll see it looks a lot like a compost pile, as opposed to a bunch of newspaper.

For my part, I love, love, love having a huge worm bin because it can easily absorb all of our kitchen waste. I can take my entire one gallon scrap pail, dig a hole in the bin, and dump it all in. When we had the small worm bin–which was made of a plastic storage bin–I could only add a cup or two of scraps at a time. This made the bin more of a hobby than a convenience. What’s extra cool is that those huge scrap loads vanish really fast in the new bin, whereas scraps tended to linger in the small bin.

Here’s a morbid question for you all: Whenever I add new scraps and see the old ones broken down so quickly, I recall something about an old cemetery in France, I believe, which was known for breaking down bodies extra fast, due to the composition of the soil. Mr. Google isn’t helping me recover this lost information, but I believe the cemetery was nicknamed “the man eater” or the “bone eater” or something like that. Does anyone with similarly Gothic tendencies happen to know what I’m talking about?

On outdoor worms:

Outdoor worm bins do have to be protected from worm predators–lots of critters like to eat worms, even dogs–either by weighing down the lid or latching it somehow. For now, we’re just keeping a big chunk of broken concrete on top. (Uhh…do I hear banjo music?)

Extreme temperature fluctuations are a problem outdoors. Worms like the temperatures we humans prefer, essentially. If it’s broiling out and they can’t find cool ground, they’ll die. When their bin freezes, they’ll die. Freezing is not an issue for us, but Nancy, being from Chicago, is an authority on cold. She says what happens with outdoor bins there is that when the deep freeze comes, the adult worms will die off, but the eggs will overwinter, and the bin will rebuild itself in the spring. Obviously, if you want your worm bin to function year-round in a cold climate it will have to be kept in a basement or a mudroom or somewhere where the temperatures are a little more moderate.

On the flip side, the mass of a big bin helps insulate the worms from the heat. They can dive deep, or hang out on the shady side of the bin. But it helps quite a bit if you can give the worms some shade during the summer, either by moving the bin under a tree or setting up some kind of screen to block the worst of the sun. 

Managing the waste stream:

Diverting all kitchen waste to the worm bin works well with our waste stream because of late, Erik has preferred to build his compost piles all at once–usually when we clear out our garden when the seasons change. The piecemeal additions of food scraps interferes with the timing of his compost harvest. See, if you build a pile all at once, you get finished compost much more quickly than if you add material a bit at a time. This is not to say that “bit at a time” piles are bad, they’re just slower. Now we have the best of both worlds.

Regarding the cat poop compost:

This should probably be a whole other post. But the short version is that I’ve been composting our cat litter in its own separate pile. This works pretty well, but with two indoor cats (aka pooping machines) the bin fills up fast. When we built the worm bin, Nancy had us harvest some of the older, more finished kitty litter compost from the bottom of the cat pile to mix into the worm pile as a base material, and I will continue to do this whenever our cat bin overfloweth. The ability to transfer some of the mature material to the worm bin will function as sort of a pressure release valve on our cat pile, allowing the whole system to work better.

Is this safe? I’m not going to say it is. I’m not going to recommend that any of you do this. When it comes to composting pet or human poo, we believe good composting technique, worms and time make all things well. But obviously if this is done badly, it could be quite dangerous. If you’re interested in extreme composting, as always, I recommend you visit Joe Jenkins’ site–he’s the author of The Humaure Handbook.

So from Erik, me and the worms: A huge and hearty thank you to Nancy and to all the class attendees who helped us make this wonderful bin!

4 Vermicomposting Tips

Ecological landscape designer Darren Butler has been teaching a series of classes at the Root Simple compound this month (I think there may be a few open slots in his Intermediate Organic Gardening class if you’re interested. Click here for details). Darren dropped a few vermicomposting tips during the beginning class that we thought we’d share:

1) Worms don’t like empty space in their bin. They dislike voids. They appreciate it very much if you bury their entire working area under a very thick layer of light dry carbon material, like shredded newspaper or chopped straw. Yes, it’s standard practice to put a layer of cover material over the scraps–but the difference here is that Darren recommends that the cover layer should fill all the empty space in the bin, from the worm level to the lid.

To be clear, you never want the bin’s working material (worms, scraps, etc.) to get super deep. That’s just asking for problems, because the deeper that material, the more likely the bottom is going to turn nasty and anaerobic. What we’re talking about here is filling the empty air space with dry matter–sort of like an insulation layer.

2) Harvesting worm castings (separating the worms from the castings) is always a bit of a challenge. Well, not challenging as in hard, but challenging as in requiring patience. Our method has been to mound the castings into a pyramid outside on a sunny day. The worms instinctively work their way down to the base of the pyramid to avoid the light. Once they do, we take off the top and sides of the pyramid and transfer that to a bucket. That material will be mostly worm free. Then we reform the pyramid and do it all over again.

This method is fine, but Darren’s method is a little faster. It works on the same principle–the photosensitivity of worms–but instead of making pyramids he lays out softball sized mounds of castings. The worms will cluster at the bottom of the balls, allowing you to harvest off the tops and sides. This works faster than our pyramid method because the worms don’t have as far to move. You can harvest faster, and get it done all at once instead of forming and reforming the pyramid.

Of course when you’re doing either method you should remember the worms are very vulnerable when they’re out of their bin like this, vulnerable to heat and sun–you don’t want to forget about them!–and also to predators like chickens, birds and even dogs.

3) Some of you have worm bins with spigots for collecting “worm tea” aka leachate. Did you know it goes bad within 24 hours of production? If you use it, use it right away. Never use undiluted leachate on plants–it can harm them. To use it on plants, dilute it with 4 parts water, put it in a spray bottle, and spray on foliage. They’ll uptake the nutrients through their leaves. Alternatively, you can use it as a soil drench (for watering) when diluted with 16 parts water. In its straight form it can be used as an insecticide.

4) Darren’s favorite way of using worm castings is new to us and quite interesting. Castings are fertilizer, but more than that. They can help bring life to your soil. He takes golf ball sized plugs of fresh castings and buries them here and there in his garden beds (or pots). Used this way, they are little beneficial microbe arks that will help invigorate the life of your soil. A little bit goes a long way. You are, in effect, inoculating your soil with microbial life.

New to worm composting, or just vermi-curious? The classic book on the subject is Worms Eat My Garbage: How to Set Up and Maintain a Worm Composting System by Mary Appelhof.
.

Vermicomposting Class

If you live in or around LA, we encourage you to take this unique class that we’re hosting in the Silver Lake area. While it’s pretty easy to get basic information on starting a worm bin, it’s rare to be able to dig deeper, especially with a teacher as knowledgeable as Nancy Klehm.

GET YOUR LOOP ON!
A workshop on extreme vermicomposting for the city dweller.

October 23, 2011
9am – 1pm

This class is suitable for both beginning vermicomposters and experienced ones with interest in integrating their worm bin with their larger household systems.


As cities struggle with basic recycling programs, and citizens learn how to grow tomatoes for the first time on their decks in soil from stripped from farmland and purchased at a store, there are some who are curious about having a more intimate connection to their waste and unveiling its worth.

In this workshop we will go “beyond the bin” and build a large, outdoor vermicomposting system designed to handle both kitchen and yard waste. The basics of worm farming will be covered, but emphasis will be placed on integrating the worm bin into the wider ecosystem of yard and house, such as:

* How to combine vermicomposting and thermacomposting in stepped systems
* How to integrate vermicomposting with a dry toilet or pet waste composting system
* How to best use your castings in the garden
* Tips for the apartment dweller
* What to do with all those extra worms…

And more!

Nancy Klehm is a long-time urban forager and grower, ecological system designer, artist and intrepid soil builder. She spent over five years designing and running a closed-loop vermicomposting project in Chicago that used 100’s of thousands of worms to digest 10’s of thousands of pounds of food and paper waste to create healthy soil. She started The Ground Rules, a community soil building center in North Philadelphia and developed and ran a two year collective human waste recovery project Humble Pile Chicago. She is the on-going bio-instigator of soil systems at C.L.U.I.’s South Base in Wendover, UT.

www.spontaneousvegetation.net
www.socialecologies.net

The Cat Poop Portal: Litter Box Composting, Installment #1

View up the side yard, looking toward the back yard. The new bin is all pretty and shiny.

Mrs. Homegrown here:

I posted about cat litter composting a while back, and got lots of interesting comments and suggestions. If you’re researching the topic, I suggest you check out that post, the comments especially.

Since then, Erik and I have decided on the method we’re going to try. We’re just going to do straight up, classic composting, Humanure Handbook style. The only difference between this style and ordinary composting is that we’ll let this compost rest for two years before we spread it, to be sure the bad beasties die off. And in case they aren’t gone, we won’t spread the finished compost around edible plants.

No, this is not orthodox practice. It is not considered “safe” to compost pet waste–all the standard advice tells you not to– but we’re doing it anyway, because we trust time and bacteria and worms and our own composting skills to make good compost out of cat litter. Also, the standard advice is mostly in reference to a home’s one-and-only compost pile. You would not want to add cat or dog poop to your regular compost pile. It needs to be kept in a separate pile that is managed more carefully.

The biggest challenge in this scheme for us was figuring out where to put yet another compost container. Our yard is already overrun with barrels and bins. Worse, when we thought it through, we realized we needed room for not just one compost bin, but at least two, maybe three, because of the aging issue.You know, fill one up, set it aside, start on another. The barrels pile up!

The solution is our south-facing side yard. That “yard” is a 3 foot wide strip of sun-baked soil that no one ever sees. It’s divided from our neighbor’s side yard (also rarely used) by a hedge of tenacious jade plants. There is no access to the back yard from the side yard. It has been a wasteland for all the time we’ve been here. This year Erik put in two tiny raised planters there to see if he could grow hops on the side of the house. But it is still mostly unused, invisible space–perfect for compost bins.

The only problem was access. It’s an awkward hike around the front house to get to that side yard. It would be no fun to have haul the dirty litter over there. This is where Erik’s genius came to play. He decided to cut a hole in our back yard fence–a little section of fence convenient to our back porch– and make a small door that will let us dump the litter directly into the barrel, which sits on the opposite side of the fence. We’re already calling this the Cat Poop Portal ™.

The Portal from the back yard, looking down on the drum

 The specs:

  • We’re composting in a food grade plastic 55 gallon drum, which we found on Craigslist. It once held brown rice syrup. I prefer to use food grade plastics for compost, especially since we’re dealing with used barrels. Better food residue than chemical residue. 
  • Our drum is white because white was all that was available. I’ve heard white degrades more quickly than the blue or black. Don’t know if that is true, but I have also heard that the lifespan of the drum can be extended by painting or covering it with a tarp. We may do one of those things.
  • Erik sawed off the top of the drum, because it wasn’t the type with a screw off lid. Rather it had a bung hole configuration. (I’m still trying to become blase about tossing around the term bung hole.) This means we don’t have a lid. We’ll just put a piece of cardboard or wood on top, because we’re classy like that. 
  • We drilled lots of 1/2″ air holes in the drum, on the sides and bottom, for air flow.
  • We put a thick layer of straw at the bottom, before we added the first deposit of litter, to provide a little ventilation from the bottom. The barrel is sitting on soil, to allow worms and bugs access.
  • Once the straw was down, we added our accumulated litter. (Yep, that’s right, I’ve been saving my cat box cleanings just this occasion. Waste not want not!) See my thoughts below regarding types of cat litter. Then we wet down the litter really well, and covered it with a topping of clean straw, and topped the drum with a piece of wood. Let the decomposition begin!
  • Note:  Never place a place a poop-filled compost bin near vegetable beds, due to the possibility of bad bacteria leaching through the soil. Ours is remote from anything edible.
The holes inside the 55 gallon drum

Thoughts on the composting:

As I said at the beginning, this is pretty much straight up, normal composting, with the exception of a long aging period at the end. The Humanure Handbook is a good general guide to composting principles as well having special instructions regarding the safe handling of poop. If you don’t know how to compost, I’d start there. That book is widely available, and they have a free pdf on their website. See our resources tab. 


Our cat litter is compostable–we’ve been using both Feline Pine and Yesterdays News–pine and paper, respectively. Compostable litter is made up of a true carbon source–that means plant-based material: corn, wheat, paper and sawdust are all okay. Clay litter, or anything with chemicals in it, would not be appropriate for this. Clay is not toxic, it’s just that it wouldn’t ever break down into proper compost. I don’t know what the clumping kind is made of, so I avoid it–but if your clumping kind is made of unadulterated carbon material, by all means compost it. Litter with baking soda added isn’t a good idea, because it’s salty. Soil does not love salt. I also avoid anything with added scent, because the chemicals used in fragrances are not something I want transferred to my soil.

We’ll soon find out what the carbon to nitrogen ratio is in the typical cat box. The litter is a heavy carbon source. We’ll see how it is balanced by the cat waste (nitrogen), but I suspect we’re going to have to add green stuff, like kitchen scraps, to get it to heat up and decompose. Here’s how we’ll know: if there’s too much carbon (litter), the pile will just sit there, cold and unchanging.

Another thing I predict is going to be problematic about this new cat bin is that we’ll be adding too little material, too slowly. This means it’s going to be very, very slow pile. Mass creates heat. The best piles are big piles. This might have to be addressed by bulking up the pile with material from another source.

My final concern is odor. This is within whiffing distance of both our patio and the neighbor’s window, so we don’t want any cat box miasma drifting around. Initial precautions include covering the surface of the pile with straw, and covering the top of the bin with a board. We’ll see how it goes.

Stay tuned for updates…

Emergency Toilet Sanitation

The Humanure Handbook: A Guide to Composting Human Manure, Third EditionI was asked by our local neighborhood council to talk about emergency turlets for their public safety committee. Doing some preliminary research about what our government suggests concerns me.

FEMA and, it seems, all the state and local agencies I looked into rely on a poop in a bag, throw in some enzymes or bleach and throw it into a pit approach. In a short term emergency, a day or two let’s say, this might work fine. But if the emergency stretched out longer I can see some potential problems. And the cynic in me sees an opportunity for a contractor to sell toilet and enzyme kits to government agencies.

So what’s wrong with pooping in a bag? First off, it’s disgusting, something I know from backpacking. I have a feeling people might avoid latrines set up with “poop bags” and go do their business behind a bush. And I have a feeling that the government experts suggesting this approach have never tried it themselves.

Secondly, those pits full of bags could become a serious biohazard should rats, let’s say, start pulling the bags apart or should the pit get flooded.

As an alternative to the “poop bag” I was impressed with Joseph Jenkin’s humanure approach that he explains in a series of videos he shot in Haiti after the earthquake. You can see those videos here. Essentially what Jenkins did in Haiti was to forage carbon material (“bagasse” or sugar cane waste) and use that as a cover material in the latrines. This eliminates smells and maggots. He also set up a large humanure compost pile in a refugee camp using the same bagasse material as the carbon source. The hot temperatures in the compost pile kill hazardous microorganisms in human poo. As long as you’ve got a carbon source you can keep Jenkins’ sanitation system going indefinitely. With the FEMA approach you’ve got a problem when you run out of those bags and proprietary enzyme mixtures.

One problem with Jenkins’ approach could be finding a carbon source in an urban area, but I think that’s solvable (suggestions invited!). You also need water for the compost pile but it need not be potable.

I’m no sanitation expert and am interested in opinions on this topic, particularly those who have worked in emergency situations or in impoverished communities. What I like about Jenkins’ approach is that it relies more on knowledge (how to compost, set up a latrine) than equipment. The job then is to spread that knowledge. Learning how to compost should be a skill everyone knows how to do.

Jenkins’ Humanure Handbook: for purchase or free pdf download.

Are Pallets Safe to Reuse?

Now you know. Pallet parts have names.

As a fan and proponent of reusing pallets in building projects, such as chicken coops and compost containers, I’m often asked if I think they are safe to use given that shippers and manufacturers fumigate them with pesticides.

In the United States quarantine regulations require that pallets be treated with methyl bromide, a pesticide being phased out due to its adverse effects on the ozone layer. According to Mary Howland Technical Service Manager at Great Lakes Chemical Corporation, a supplier of methyl bromide,

Methyl bromide products are restricted use pesticides. A certified applicator license is required to purchase and use these products and strict adherence to label directions/requirements is mandatory. Under normal fumigation conditions methyl bromide is a gas and when the pallets are properly aerated according to label instructions, virtually no methyl bromide residue remains on the pallets and wood materials.

Now I’m not a methyl bromide fan and I find it’s use as a soil fumigant in agricultural applications appalling.  But I’m not too worried about reusing pallets. That being said, a Tylenol recall was linked to the use of tribromophenol (TBP) to fumigate pallets. Though, depending on if you believe the trade organizations behind wood pallets or plastic pallets (they hate each other), the Tylenol recall may have had nothing to do with TBP which is not used to fumigate pallets in the US.

So, as with most issues on this blog, no easy answer. But I’m still not concerned about using pallets as a building material.

More Pallet Composters

Thanks readers for sending links to some attractive pallet compost bins. The one above is at http://thriftify.wordpress.com/2009/03/12/easy-to-build-pallet-compost-bin/.

Another nice one at http://www.ecodaddyo.com/node/94, though I like to keep the bottom open and the compost in contact with the ground. Correction: the bottom is open on this composter.

It ain’t made of pallets but it looks like it will work nicely and you sure can’t beat the scenery. From Devon Morgan.

Compost Bin Project From Our New Book

Natural Home and Garden magazine has excerpted a shipping pallet compost bin project from our new book Making It: Radical Home Ec for a Post-Consumer World.

I’ve been using shipping pallets as a compost bin for a few years now and they work great. A compost pile, in my humble opinion, should be a minimum of a cubic yard in order to jump start the heat and microbial life that makes for good compost. Nail together a couple of pallets and you’ve got a cubic yard sized pile. 

I’ve got two bins, side by side, but wish I had three. Mine also look like hell since I put them together in a hurry. I much prefer the bin the folks at Motuv in Kansas City created:

To answer ahead of time a question that always comes up–am I concerned about contaminated pallets? In short, no. A longer explanation will have to wait for another blog post.

Leave a comment on how you store compost. And if you’ve got an aesthetically pleasing bin I’m especially interested. Leave a link to a photo.

Cat Litter Composting

Pocket Nitrogen Generator

 Mrs. Homegrown here:

Apologies to you googlers looking for solid answers. This is what Erik calls a probe. I’ve decided to compost our kitten’s litter box waste, and this is how I plan to go about it. However, I’m sure I’ll learn a lot as I go, so this post isn’t instructional. I will post a report once the system gets going.

The real reason I’m posting is because I’d love is to hear from any of you who do this already–tips are much appreciated! I’m particularly interested in finding a good brand of litter that composts well.

The basic gist:

Okay, first, anyone who’s gone through Composting 101 knows they say not to put pet waste, especially dog and cat waste, in your regular compost bin. This is because cat and dog poop contains pathogens. We never composted our late dog’s waste, and for 12 years we sent at least two big plastic bags of poop to the landfill every day. Parents who use disposable diapers got nothing on me in terms of environmental guilt.

Now we’ve got this cat, and I’m looking in her litter box and seeing nothing but carbon and nitrogen. I can’t stand it. I’m disregarding Composting 101 rules because I know this can be done, if done carefully. Over the years I’ve learned to be amazed by the Cleansing Power of Compost & Time, especially since we started doing some humanure composting. Check that link for more info on Jenkins’ good work in that area–research, technique, message boards, etc. It’s all there. Human, cat and dog waste are all more tricky to work with than your more benign chicken and bunny waste. This isn’t something one should do in a half-assed way, but it is possible.

The plan I’m going to follow is the basic humanure model, which is classic composting, but with lots of attention and care, followed by a 2 year rest period for the full bin, during which time worms and bacteria do their scrubbing magic to help remove any lingering nasties. When the first batch is done, I’ll have a sample lab tested, just out of curiosity.

Whatever I do, I won’t spread my finished compost on food crops, but instead under our trees and around our perennials. 

I have considered doing this via a worm bin, but as I understand it, the worms don’t like the fresh pet waste–and understandably, too! They like to come in when it’s broken down a bit. I’ll definitely add worms to the bin when the rest period begins. But if anyone has a pet-waste worm bin, let me know how that’s going!

Now I have to find a spot for (yet another) bin of poo in our yard.

(Do I hear the soundtrack to Deliverance playing, or is that just my imagination?)

Update: Read what I decided to do in The Cat Poop Portal