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

Deep Bedding for Chickens

We’ve got about 5-6″ of loose stuff on the floor of our chicken run. Underneath that, it’s black gold.

Around this time of year, folks are getting chickens. Some for the first time. So I figured it was time to talk about deep bedding again. I know we’ve written about it before, in our book, or on this blog, but this advice bears repeating:

Nature abhors bare ground. 
Line your chicken coop and run with a thick layer of mulch.

Doing this is called “deep bedding.”

Deep bedding solves a whole lot of chicken-related problems in one easy step:

  • It goes a long way toward controlling odor. 
  • It reduces flies (it not only absorbs poop, it actually fosters parasites that kill fly eggs)
  • It makes the coop area much more attractive to look at. 
  • It gives the chickens more to do (ie scratch) which keeps them happy, which keeps them from developing bad behaviors
  • It saves you work, because you don’t have to clean it out very often. Maybe not at all. Depending on your set up.

(This is a little off topic, but in a similar way we also advocate thick mulch over any bare ground in your yard. It will improve the soil, encourage worms, discourage weeds, conserve water, etc. If we had lots of spare time, money and a big truck, we’d drive around LA dumping mulch on the many, many parched landscapes that desperately need it.)

    How deep? What do I use?

    The deeper the better. Say 4 or 5 inches to start, and you will add more to that as it breaks down. As to what to use, you can use any dry organic matter–leaves, husks, straw, dry grass clippings, pine needles. We use straw, and a lot of dead leaves fall into the run, too.

    If you want to use straw, try this: just toss a few flakes* of straw into the center of the coop, and the ladies will do all the work of distributing it for you. Scouts honor. Go away, come back in an hour, and it will be so level and even, it will look like you spread it yourself.

    Start to think about your chicken coop/run as a compost pile rather than as an animal enclosure. That is what it will become. The chickens break down the bedding material, all the veg scraps you give them, and their own manure, through their constant scratching. Over time, the floor of the coop and/or run becomes a deep soft deposit of compost. Ours is sort of like quicksand. We throw all sorts of stuff in there–kitchen scraps, huge stalks of bolted lettuce, armloads of nasturtium, squash rinds–whatever goes in vanishes within a day or two. The hens peck at it until all the good stuff is gone. Then they trample it. Then they bury it. It all becomes one.

    Wear and weather break down the bedding, so you will need to add fresh material every so often. You may also choose to harvest the compost that accumulates in the run. When you do so is up to you. We don’t harvest more than once a year, but your mileage may vary. When you do clean it out, replace what you took with lots of new bedding.

    You will probably want to transfer what you harvest into a compost pile to finish up before it goes into your garden.

    Note: The hen house is different

    Our hens don’t spend any of their waking hours in the hen house, except to visit in the laying box. This means they never scratch around in there, which means this whole “living compost” system just doesn’t work in the house. The poop remains where it falls beneath the roost, untouched. Because of this, we have to clean the house out regularly. To make clean up faster, we don’t use straw or leaves inside–though we could–instead we use wood shavings, because those scoop out fast and easy, like a cat box. The soiled litter goes into our compost pile.

    Hens so hot, they had to be put behind bars!

    *Flake, a vocab word: Straw bales are compressed in such a way that when they are unbound, they come apart in sections about 4 or 5 inches thick. These are called “flakes.”

    Hugo, humanure and nettles

    One of the original illustrations to Les Misérables (1862)

    Mrs. Homegrown here:

    Anne, our neighbor with the pea-ravaging Chihuahua, brings to our attention the fact that Victor Hugo was a humanure enthusiast, and in fact dedicates long passages of Les Misérables to it.

    This is taken from Volume V, Book 2 (The Intestine of the Leviathan), Chapter One, provided by Project Gutenberg:

    Paris casts twenty-five millions yearly into the water. And this without metaphor. How, and in what manner? Day and night. With what object? With no object. With what intention? With no intention. Why? For no reason. By means of what organ? By means of its intestine. What is its intestine? The sewer.

    Twenty-five millions is the most moderate approximative figure which the valuations of special science have set upon it.

    Science, after having long groped about, now knows that the most fecundating and the most efficacious of fertilizers is human manure. The Chinese, let us confess it to our shame, knew it before us. Not a Chinese peasant—it is Eckberg who says this,—goes to town without bringing back with him, at the two extremities of his bamboo pole, two full buckets of what we designate as filth. Thanks to human dung, the earth in China is still as young as in the days of Abraham. Chinese wheat yields a hundred fold of the seed. There is no guano comparable in fertility with the detritus of a capital. A great city is the most mighty of dung-makers. Certain success would attend the experiment of employing the city to manure the plain. If our gold is manure, our manure, on the other hand, is gold.

    What is done with this golden manure? It is swept into the abyss. 


    Fleets of vessels are dispatched, at great expense, to collect the dung of petrels and penguins at the South Pole, and the incalculable element of opulence which we have on hand, we send to the sea. All the human and animal manure which the world wastes, restored to the land instead of being cast into the water, would suffice to nourish the world.

    Those heaps of filth at the gate-posts, those tumbrels of mud which jolt through the street by night, those terrible casks of the street department, those fetid drippings of subterranean mire, which the pavements hide from you,—do you know what they are? They are the meadow in flower, the green grass, wild thyme, thyme and sage, they are game, they are cattle, they are the satisfied bellows of great oxen in the evening, they are perfumed hay, they are golden wheat, they are the bread on your table, they are the warm blood in your veins, they are health, they are joy, they are life. This is the will of that mysterious creation which is transformation on earth and transfiguration in heaven. 

    I’ll stop there, but it goes on…and Anne says he brings it up again later.

    As I recall, Hugo also had a thing for nettles….hey, wait a minute! Turns out that his rant about nettles is in Les Mis too:

    One day he saw some country people busily engaged in pulling up nettles; he examined the plants, which were uprooted and already dried, and said: “They are dead. Nevertheless, it would be a good thing to know how to make use of them. When the nettle is young, the leaf makes an excellent vegetable; when it is older, it has filaments and fibres like hemp and flax. Nettle cloth is as good as linen cloth. Chopped up, nettles are good for poultry; pounded, they are good for horned cattle. The seed of the nettle, mixed with fodder, gives gloss to the hair of animals; the root, mixed with salt, produces a beautiful yellow coloring-matter. Moreover, it is an excellent hay, which can be cut twice. And what is required for the nettle? A little soil, no care, no culture. Only the seed falls as it is ripe, and it is difficult to collect it. That is all. With the exercise of a little care, the nettle could be made useful; it is neglected and it becomes hurtful. It is exterminated. How many men resemble the nettle!” He added, after a pause: “Remember this, my friends: there are no such things as bad plants or bad men. There are only bad cultivators.”



    I’ve never read Les Misérables, but I’m beginning to think it should be required reading–just for his asides. It’s time to face my PTSD from the musical and embrace the book–all three billion pages of it.

    Build a Worm Tower

    Host: Leonnie Shanahan. More info: www.ecofilms.com.au

    Mrs. Homegrown here:

    One of our commenters on the compost debate, Nick H., offered up a link to a great video about worm towers, so we thought we’d share. A worm tower is a wide (at least 50cm dia.) pipe sunk halfway into the ground, with access holes on the lower half to allow the worms to come and go. Food and bedding is dropped in the top, which is kept capped.

    We happen to have worm & compost expert Nancy Klehm staying with us this weekend, and she explained to us that this particular technology makes a lot of sense for hot, dry climates (note the video comes from Australia), because it’s sunken and it allows the worms to distribute themselves in the cool soil during the day. Conversely, I can imagine this wouldn’t be such a great thing in rainy climates as it could easily flood.

    Nancy told us the worm holes clog up, so you do have to remove the pipe for cleaning fairly regularly, and perhaps take that opportunity to reposition it. I imagine that’s when the casting harvest would occur, and harvest promises to be a pretty messy process. 

    The video speaks of using PVC pipe for the tower. PVC is cheap and easy to work with, but it’s pretty well established that it leaches toxins as it degrades, so you might want to seek out pipe in other materials. As an aside, we used to use PVC pipe in our self-irrigating pots, still still have PVC in some of them, but are phasing it out in favor of metal or bamboo pipe. Yet we still have PVC lines as part of our irrigation system. This is something you have to weigh and decide for yourself. 

    Once Erik dragged home a section of ceramic sewer pipe he found in the street. It lingered in our yard for years, and was finally returned to the street. Now we’re singing the pack rat’s lament (See! See what happens when you throw things away!), because it would have been perfect for this.

    On first glance I’d characterize this system as a novel idea, one which is worm-friendly, and best suited to hot, dry climates. It looks convenient to set up and use, but probably not the best system to use if you’re primarily interested in the castings.

    If we can find another length of sewer pipe we’ll try it out and report back.

    Compost Rebuttal

    Kelly’s secret compost pile.

    I found out via a blog post last week that Kelly had secretly constructed a compost pile to deal with a surplus of kitchen scraps. She knew I’d be unhappy with this due to my anal retentive approach to composting.

    So why am I unhappy with this pile? The reason is simple: it’s too small and will never generate enough heat to:

    • Kill weed seeds.
    • Kill human and plant pathogens.
    • Kill root nematodes.

    Don’t just believe me, listen to soil scientist Dr. Elaine Ingham in this youtube video:

    Ingham’s work is controversial, but I believe time will prove her ideas correct. To grow fussy plants like vegetables we need to introduce beneficial microorganisms and fungi into the soil via well made compost. To make that compost we need to monitor the pile’s temperature carefully (it should be between 55ºC and 65ºC for at least three days according to Ingham). The pile also needs oxygen, provided by introducing loose materials like straw and through periodic turning. A compost pile needs water too. It’s not difficult to achieve the conditions Ingham specifies. You just need enough mass combined with the use of a compost thermometer to figure out when to turn the pile. 

    O.K., so now I’m headed out into the garden to combine that tiny and ugly tire pile to the new pile I’m building.

    For more information on Ingham’s work read, Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web, Revised Edition by Jeff Lowenfels and Wayne Lewis.

    Mrs. Homegrown here:

    Just rebutting the rebuttal. I don’t disagree with anything Erik says above, and Ingham’s work is fascinating.  But to be clear about my post, the “sooper seekrit” pile was not about producing compost, it was about disposing of waste. Indeed, such a small pile does not have the mass to heat up enough to burn off nasties or to decompose very quickly, but it suited my needs at the time. Homemade compost is a wonderous thing. It’s vital to organic gardening, and moreover it’s really satisfying to take the waste products from your kitchen and garden and make them into something which will build your soil. You get to keep all that wealth close at hand. However, if you don’t want or need compost for your garden, but you don’t want to send green scraps to the landfill, you can return it to the earth in more casual ways, like the sooper seekrit pile.

    My Sooper Seekrit Compost Pile

    Welcome to the Lucy and Ricky show!

    As some of you know, Erik is a complete and utter compost wonk. A heavy book about the science of decomposition is pleasure reading for him. He has a really, really big thermometer and knows how to use it.

    We’ve kept a compost pile for years and years, but only in the last two years has it become an obsession for him. One of his more recent projects has been to make an gigantic bin in our back yard. This is the sort of bin you could use to dispose of bodies. He became so persnickety about the proper usage of the Wonder Bin that I was afraid to take scraps out there. Emptying the compost pail became his duty.

    Then, one day, something went wrong in compost nirvana. You’d have to ask him for the details of his crisis, but the upshot was that he didn’t want anything new to go in the bin.

    “But…but…” I said, pointing at the full compost pail on the counter.

    “I’ll deal with it,” he said.

    One day passed, and the next. He put a big mixing bowl on the counter next to the overflowing pail and started throwing his scraps in there. Flies gathered. 10 lbs of rotting scraps on the counter bothers Erik not a whit.

    Of course the notion of putting it all in the trash never crossed our minds. At this point, it’s unthinkable, like driving around without a seat belt.

    “This can’t go on,” I said, when a second mixing bowl of scraps joined the first, and the fruit flies started passing out party fliers to the whole neighborhood.

    “It will have to go in the green bin,” he said with an air of grim decision.

    The green bin is the dedicated wheelie bin given us by the city to collect green waste. We use it only for green waste we can’t compost, partially because we need as much compost as we can make, and partially because I hear the city often uses the green bin material as landfill covering.

    I just couldn’t put it in the green bin, so I went out in the back yard, collected a couple of the old tires rolling around back there (we’re classy that way), stacked them up under the avocado tree and started my own alternative compost pile.

    I did not tell Erik about the AlternoPile because I knew he’d squawk about it. “There’s not enough mass!” he’d protest. Or maybe he’d cry, his face blanching with horror, “Your nitrogen inputs are way too high! For God’s sake, stop this madness!”  

    Sometimes things just gotta rot without you thinking about them, you know?

    I also was not worried he’d discover my sooper seekrit pile because Erik has a particularly advanced form of man blindness. He couldn’t find a boa constrictor in the fridge. I don’t have to hide his Christmas presents. And I figured a couple of tires under the tree were not going to attract his attention for a long while

    To his credit, he did notice it, after a couple of weeks, and asked, “Did you plant something in the tires?” Because I was in the bathroom and didn’t have to look him in the face I was able to say, “No honey, I didn’t plant anything in the tires.”

    He investigated no more, and the secret pile continued. Yesterday he finally rebuilt his compost pile, and now it’s accepting scraps again. The game is up.  I’ll let the tires sit and stew. In a few months I can move them and will leave behind nothing but a little pile of compost.

    The moral:

    If you’ve been thinking you can’t compost because you don’t generate much green waste, or you don’t have space for a big bin, or just don’t want to screw with it,  I’d say try it anyway. My two tires absorbed our green waste for weeks, and would have continued to do so. That’s kitchen waste for two people who cook a lot, but no yard trimmings, obviously.  I’d dump the pail in there, and cover the scraps with handfuls of hay or dry leaves.

    Sometimes the level would raise high, but this stuff shrinks fast, so it maintained a level one tire deep most of the time, and would have done so until compost started building up at the bottom. Eventually I would have put the top tire on the ground and shoveled the contents of the bottom tire into the top tire, basically turning everything upside down. This would speed things along a bit, and would reveal any finished compost at the very bottom.

    Caveats: This system doesn’t generate heat through mass, so will be much slower than a real compost pile. It is best used when the weather is warmer to help things along. And again, this isn’t what you do if you want compost for your garden. This is just one way to quietly return your kitchen waste to the earth.

    When Erik sees this post he’s going scream, “Luuuuuucy!!!!” and proceed to write a rebuttal explaining why a tiny compost pile is a bad idea, but no matter what he says, I believe composting can be as simple as this.

    So I had this dream

    Here I am, with the soon-to-be-forgotten worms and a fantastic class of Waldorf kids

    Mrs. Homegrown here:

    So last night I had this dream that I was sitting at a kitchen table with someone (don’t know who it was) and I noticed something that looked like a dried out worm coiled on the edge of one of the dishes. I pointed it out to this other person, and she reached out and crushed it with her fingertip. It crumbled to pieces on the tabletop. I laughed and said, “I sure hope that’s not one of my worms!” She laughed, too, and mischievously blew the crumbs in my direction.

    And thus does one’s subconscious work. I woke with a start, remembering that, after showing off my worms to class of visiting school kids, I’d left the bin out on the back porch for a night, and day, and half of another night. Usually the worms live in the kitchen. I jumped out of bed and brought them back in.

    The problem with worms is that they’re so darn quiet.

    The worms are fine. They’re tough, and our weather is mild. But I was a little worried about them  because they are house-worms, acclimated to room temperature, and I’d left them out in the open, on concrete, and in a shallow bin.

    See, worms can take care of themselves just fine if given the room and resources they need to cool themselves down, warm themselves up, and regulate their moisture. However, when they’re in a shallow little bin, they just don’t have much latitude for adjustment. It’s our responsibility as worm keepers to regulate their environment.

    Luckily for us and our forgotten worms, even though it was unseasonably warm yesterday,  the sun is low on the horizon, so our back porch wasn’t baking in the western sun, like it does most of the year. Otherwise, the worms, being unable to hide deep in the soil, might have steam cooked in the bin during that long, forgotten day. 

    Of course, worms can be kept outdoors in all but the most extreme temperatures, but their bins need to be sited correctly–kept in nice shady spots, protected from the rain, and elevated from cold-conducting cement surfaces. (Maybe some of you folks who live in snow country could chime in on what you do with your worms when it’s freezing out?)


    Learn How to Compost Via the Humanure Handbook

    The Humanure Handbook: A Guide to Composting Human Manure, Third EditionComposting ain’t rocket science but it does require some finesse. Following up on an earlier post which contained a comparison of different composters, I thought I’d mention my favorite written resource on how to compost. In my opinion, the best writing on the subject comes from a surprising source, the Humanure Handbook by Joeseph Jenkins. Best of all, an edition of this book is available online for free. Even if you have no intention of composting human waste, The Humanure Handbook contains excellent directions on how to easily maintain a hot n’ healthy compost pile. You can access the free edition here. Jenkins also has a bunch of great how-to videos here.

    On the subject of humanure, news coverage of the terrible cholera outbreak in Haiti only gets half of the story. I keep hearing the press refer to the problem as one of a “lack of access to clean water.” True, but the other half of the problem is what Jenkin’s Humanure book is about, keeping human waste out of waterways in the first place and turning it into a resource rather than a disposal problem.

    Extreme Recycling

    Over at Edible Geography a post, Upgrade Excreta, on three artists and designers working with human waste. Above, design student James Gilpin, who has allegedly figured out how to turn the pee of elderly diabetics into fine single malt scotch. Now that’s what I call recycling!

    Meanwhile, Chicago artist and activist Nancy Klehm has completed her Humble Pile humanure project, releasing a stunning t-shirt in the process.

    Lastly, designer Tobias Wong has created little glittery pills that make your poop sparkle.