Way to Compost 3: The 3 Bin System

As an intern on an organic farm, I used to compost a lot of raw farm material. The farm was certified biodynamic, which meant that as much as possible, we strived to be a closed system—a farm “organism.” Very few inputs came in (coffee and chocolate were the much needed and celebrated exceptions), and no outputs went “out.” We had to take care of our own outputs, if you catch my meaning.

Imagine the farm as an organism. Humans and animals eat plants and grasses, burn energy, and leave behind various forms of waste. Trees take in carbon dioxide, burn sugars, and give off oxygen. Worms eat decaying material, pass it through their marvelous guts, and leave humus as waste. On the farm, weeds, grass clippings, used water, sheep wool, chickens that did not run for cover from the hawk, leftover milk, garbage, manure, and yes, even our own “humanure” were all waste streams that needed to be transformed into usable energy once again. Constant compost!

In order to keep all of these outputs organized for the composting process, we used the 3-bin system. This could be anything divided into three separate sections, often by moveable pieces of lumber such as pallets or boards. Strawbales are also a good material for building the bins. Once strawbales start to decay, you can just add them to the compost.

The bins were at least 3 cubic feet, and needed enough space in the front for a person to use a shovel or front loader to turn the pile form one bin to another. Placing bins in the shade is a good idea, and making sure there is good drainage is also important. If it rains, compost piles tend to leach nutrients. Building the bins right onto the soil is a good solution to this problem, as long as your soil drains well. Covering the pile with straw, a tarp, or leaves also helps to keep the pile from becoming too saturated.

When compost day came, (usually every two weeks or so) all of the manure, kitchen scraps, and brown material I had stored in the first of the three bins was made into a compost pile in the middle. Here’s how I made it:

The first layer was about an inch of chopped sticks and twigs from my pile of “brown” stuff in the first bay. These provided an air pocket on the bottom of the pile for good air circulation. When the pile built heat over the next day or two, convection currents would draw air from the bottom of the pile up through the top. This provided hard working microorganisms with oxygen and kept the pile smelling pretty fresh.

After this first layer, (the crust, if you will) I filled it with a compost cake. First, brown stuff, then greens from the kitchen can or the manure piles. Next, water it if it seemed too dry. Compost piles should have the moisture content of a wrung out sponge. Then brown, green, water and so on, until I had layered all of the stored up piles of “waste” into a fabulous monster of a seven layer compost cake. I would frost the pile with leaves, strawbale flakes, or sometimes a tarp if it was going to rain a lot. This top layer shed moisture and kept off flies. It also looked very neat and tidy.

Then I let the pile sit for a couple of weeks to bake. The temperature of the pile peaked the first week at around 150 F, then it slowly declined. At the end of the second week, I peeled off the outer layer, prepared a bottom layer of twigs and sticks in the 3rd bin, and turned the pile into it. To make sure that material that may have been left on the outside of the first pile had time in the middle, I shoveled vertical “slices” of the compost cake, from right to left, into horizontal layers from bottom to top. Farmers with front loaders have their own methods for making sure all the material gets a chance to be in the hot seat. This was my from scratch, by hand method.

By the time I turned the pile from the 2nd to the 3rd bin, the first bin was already filling up with more brown stuff, the cows and chickens were piling up more manure, we had eaten and left behind plenty of kitchen scraps to use again, and the middle bay was waiting to be filled. Waste streams do not take vacations.

The 3rd bay got two more weeks to be worked on by bacteria, fungus, and other microorganisms in the pile. It fermented while the new compost cake in the second bay cooked. When it smelled done, earthy and mushroomy and energizing, I moved it into the garden beds or under some trees until we are ready to use it. During the winter, the bays can store browns and greens until the earth warms up and compost organisms are in abundance and active again.

This 3 bin system works beautifully if you have a front loader to turn the compost–or if you want to skip your gym membership and do lots of shoveling instead. It works well for those who have a lot of material they need compost fairly quickly on a regular basis (community gardens) and have time to make, turn, and use several piles a year—or for those who have a very willing and enthusiastic intern. 

Stay tuned for more ways to compost as the winter turns a celestial corner to spring.

Compost where?

There are two important places where compost happens in nature: the forest floor and inside stomachs.

The forest floor is a slow, sweet smelling compost pile we call duff.  Duff even sounds muted and mysterious, a substance with tiny secrets and tantalizingly familiar smells. Leaves created through the miraculous process of photosynthesis—a process made possible by a bacteria containing chlorophyll that can capture light to make energy and food—fall back to the earth and are broken down by earthy critters into smaller and smaller pieces until they become food for soil microorganisms.  This transformation has sustained forests for thousands of years.

The first shredders.

could you hear them if you paused,

ear to the ground, like the popping sound

of fish munching on coral underwater?

All of Mother Earth is being savored,

tasted, taken in, from forest to ocean to farm,

teeth and jaws gnawing away on our giant earthcicle,

passing particles through guts, working them deeper

and deeper into the ground until what once was leaf or twig

or even beetle or bone has become so small that soil microbes,

bacteria and fungus and slime mold, are able at last to access energy,

metabolize fallen sunspots, release stardust

back into soil where tree roots are waiting like open hands

to carry nutrients up and up to the canopy to be

knitted into next year’s leaves.

Slime mold: it appeared in the garden out of nowhere and has never been seen again!

These microscopic bodies live, transform, and die without being seen in order to move the wheel of life forward. To take what is dead and transform it into a spark of life. A wonder. This is bodily, physical, and it can make us uncomfortable. It can turn our stomachs.

And our stomachs are the other place compost happens in nature. Stomachs and intestines combine to make an oxygen deprived compost tank inhabited by millions of microorganisms. The most efficient stomachs belong to ruminant (“room-in-it”) animals. They include sheep, goats, giraffes, deer, and llamas. Ordinary as they are, the inside of a ruminant’s stomach holds another one of life’s great mysteries. Ruminants can miraculously turn plant nitrogen into protein with the help of bacteria that scientists believe to be over 3.6 billion years old (archaebacteria), fungi, and protozoa.

Cows are the most widely known and underappreciated ruminants I know.  With a four part stomach—the rumen, reticulum, omasum, and abomasum—cow manure is the best example of barrel turned compost on four legs. The first compartment of a cow’s stomach, the rumen, is the size of a barrel.  It can hold up to 40 gallons of material and 25-30 gallons of salt-filled saliva are sent down there every day to balance the rumen’s pH.  Just as in a compost pile, the smaller the fiber the more completely and efficiently it composts.  So, what goes into the rumen is often sent back up for further chewing, for rumination.

Perhaps the bovines ruminate on their bacterial partners, how their partnership came to be.

Cows eat raw grass but, ultimately, they are feeding the microbes that live just down the tracheal street. Those toothless wonders need the grass to be chewed for them before they can get to work. On the forest floor, beetles and worms do the work. In a stomach, the organic material arrives pre-chewed, opening the way for them to extract all kinds of nutrients from it. Some they give to the cow, but a lot of it they keep for themselves, to give them energy and to make protein for their bodies. The microbes living inside the cow turn nitrogen stored in plants into protein, not the cow.

https://lallemandanimalnutrition.com/en/asia/whats-new/ruminant-microbiota-insight-part-1-meet-the-microbes/

Alchemists!

If you were looking for them, look no further, they reside in the rumen of ruminants. Ruminating on plant-filled sunshine. They will double in number every hour, and after a long life of a few weeks, the spent microbes are washed away into the cow’s intestines to be food for the cow. Seventy five percent of all of a cow’s protein content comes from the bodies of ancient microbes.

McDonald’s (the hamburger patty and the cheese), that charcuterie board at the winery (the cheese and the wine), the Greek yogurt for breakfast, all of them made possible by ancient microbes living out their lives inside cows.

Human stomachs don’t have the ability to turn nitrogen into protein, but we rely on a similar microbial partnership.  Just a thimble-full of large intestine fluids contains up to ten trillion microbes.  Without them, we would be unable to make K and B vitamins.  And even our own humanure is a precious resource[1].  When handled properly and with care, we can compost our own waste to use on trees, shrubs, lawns, and even agricultural crops, closing our nutrient cycle and saving millions of gallons of water by not flushing this resource down the toilet.

Our bodies have grown from the soil as much as our food has, and the microbes that make nutrients and proteins available to plants and cows and us are also waiting for us to give them our leftovers in a relationship of reciprocity. They do not care if what we give them is moldy or halfway chewed. They have no preference for a month-old piece of dried macaroni or a week old, uneaten scrap of a tostada. They only need the right conditions to break it down—the conditions found in a cow’s rumen, our own digestive tract, and the forest floor. Compost piles are a kind of external, symbiotic, second stomach in teh backyard. The same conditions that we create in our compost piles—a warm, moist, aerated mass of carbohydrates and proteins large enough to house bacteria and fungus, undisturbed for a while so they can do their alchemist’s work–breaking down our leftover food into exactly what the soil needs to grow more food. Humus.

When we add compost back to the soil, its pulse quickens. What were once food scraps have transformed into a plant root buffet, the positive and negative charges that electrify the ground, begin to stir, poised, then grow, organize, coalesce, take form, take root, reach for the sunshine to be plucked by teeth or fingers or the header of a combine, harvested and reformed into food again.

We make soil food. Soils make we food.  We feed each other.

[1] Jenkins, Joseph.  Humanure Handbook: A Guide to Composting Human Manure.  1999.  Joseph Jenkins, Inc.: Grove City, PA.

Backyard Tributary

Take a deep breath.

And another.

Now imagine this united moment: home kitchens, cafés, bistros, all-you-can-eat buffets, school cafeterias, churches, mosques, temples, food trucks, convention centers, the white house, hospitals, fast food restaurants, and food courts at the mall gather all of the leftover food…and dump it.

Flump, crsshh, trasshh!

The headwaters of Food River. Every person in the United States contributes to this monumental feature of our landscape, but not many do what we are about to do next: follow it.

The first droplets quickly become rivulets that condense into larger white and black plastic bags temporarily held in cans in kitchens and behind buildings. As the food eddies begin to swirl, rise, and gain momentum, the surface tension increases, threatening, and occasionally succeeding, to spill over its banks. To avoid a food flood, the swelling leftovers are gathered and dumped into garbage truck basins. Their motors rumble, mechanical arms lift, dump, compact and intensify the food flow.

Now imagine these fleets of garbage trucks passing by your house, 300 every hour, on their way to the transfer station, like they do in the south Bronx. Imagine the sound. The smell. In a matter of days, Food River swiftly roils into mighty rapids, rushing down a cascading ladder of larger and larger containers until it crashes against its final destination, a massive, rotting food wave mixed with other trash, engulfed forever by a landfill where it will finally lay still, stagnant, and belch 15% of the nation’s annual methane emissions into the air.

Unlike other rivers, Food River is under no threat of running dry. It courses through restaurants, houses, and neighborhoods, carrying 38 million tons of food waste to landfills every year. If we convert those 38 million tons into gallons, it would replace all of the water going over Niagara Falls for an entire month. We could survive a trip over the massive food-fall in a dumpster.

Pause your imagination for just a couple more Food River facts. It carries enough uneaten food to feed 190 million people—every day. And even though it consists primarily of food, that food carries water. Twenty-five percent of the freshwater in the United States is used to grow food that never gets eaten.

Ugh, numbers! They tell one kind of story, they quantify ‘how much,’ they get baked into pies and charts, but they do not scrape food into a compost bucket instead of a garbage can. Statistics do not build worm bins. Numbers do not dig a hole in the compost pile, dump leftovers in, and cover it up again. Numbers weigh on us, numb us, are quickly forgotten, like food waste.

But the more we throw away, the less chance we have to begin again. Food River’s current course forfeits the potential life locked up in all that organic matter. A massive amount of useful nutrients that can transform the future of food and soil and bugs and butterflies and humans.

So let’s begin with the end, with what is left, and break down into our elemental parts, our elemental selves, into the dirt and the dust, down and down until our cheeks touch the soil and our noses smell the earth and we can no longer bear to waste it. So far to the end that it becomes the beginning. Soil is food, food is soil. Let’s jumpstart into numberless, new cycles.

The water cycle: evaporation, condensation, precipitation, sublimation.

The soil cycle: food waste collection, decomposition, application, invigoration.

Compost piles are the clouds of the soil cycle.

Leftovers, one of the country’s greatest wastes, is ripe to be one of our greatest natural resources. There is an inexplicable beauty and harmony here. A beautiful equation that simply needs balancing. We need to take these leftovers and deposit them not into the landfill, but back into the soil. We need compost. And to do that, we have to divert the great Food River into our own backyards.

Take a deep breath.

And another.

Imagine this:

Dinner: made, served, shared, savored, coaxed into a few picky eaters’ mouths, cleared and stacked into plate cairns on the counter. The last thing anyone wants to do now is add more chores. It is done. Scraped. Rinsed. Let the garbage truck take it away and out of reach and sight and smell. Take it away. Take it away and never think of that last bite of bagel with cream cheese, the pickle juice in the empty jar, the crunchy rice or coconut curry beginning to split. Especially not the mildewed dinner roll or long forgotten yogurt with flecks of gray-green mold from the depths of the fridge. These are the leftovers that cannot be fluffed into something new. Leftovers destined for a plastic lined and lidded future. For the great and ever flowing Food River.

Not this time.

This time, dump them, place them, scrape them, scoop them all into a compost bin kept under your sink (or in my case, often on the counter) with glee, curiosity, thankfulness, and maybe a little bit of rebellious flair. Those smelly leftovers have a future now, a mysteriously quiet and captivating journey to new life in your yard or garage or, dare I say it, custom made coffee table that doubles as a worm bin.

Yes! Your leftovers have potential, a purpose, somewhere left to go, something left to do, and it has the power to transform the earth and us at the same time.

This blog explores many ways to divert food’s fluvial course from the headwaters of your plate to the rich compost delta in your backyard.

Let’s make clouds of compost.

Way to Compost 2: Worms

They are born, eat, breathe through their skin, and burrow beneath us in the darkness of the soil. Darwin described them as “the intestines of the earth” and went on to say that “it may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.”

Lowest of the low, or saints of the soil?

Anatomically speaking, worms are wild. Between mouth and tail, earthworms are divided into more than 150 segments. If you cut a worm on the 75th segment, it will not, as the urban myth suggests, become two worms. The head may grow a new tail, but the tail will not grow a new head. With one, long digestive tract that runs the entire length of its body, worms are born to digest. They are also hermaphrodytes, have five hearts, no need for eyes, hatch three or four at a time from a cocoon, and breathe through their skin.

But not all worms are the same. In fact there are over 7,260 species of worms. Some, like the inch-long ice worm called Solifugus (sun-avoiding), have adapted to living on the edge of icebergs in Alaska. Their ability to provide a burst of energy to their cells in extreme cold may help scientists understand how life could survive on icy moons like Europa.

One of the largest earthworms on the planet is found in Washington State, if you can find one. The giant Palouse earthworm is pinkish white and smells like a lily if you were to scratch its slimy chin, hence the name Driloleirusis, “lily-like” worm. The Palouse worm is a native species that thrives in the bunchgrass prairies, but agriculture has destroyed much of its habitat. Only one person has seen this lovely giant since 1978.


For composters, the red wiggler is the holy grail of humus and is found on every continent except Antarctica. Eisenia Fetida, which means “to stink,” loves to live in loose, rich, warm places like manure piles and worm bins. If they feel threatened, they release a yellow, stinky liquid that deters birds. But if you give them a safe place to live, time, and food, they produce manure, or castings, that contain about 50 percent more calcium, nitrogen, phosphorus, potassium, and bacteria than the surrounding soil. These castings do not stink at all. In fact, they smell like soil and feel like silk. One day, you’ll know what I’m talking about.

Each red wiggler can digest up to its body weight in one day. So, five pounds of red wigglers can eat up to 35 pounds of food waste every week! In economic terms, there is no better return on an investment. Worms are livestock that eat leftovers we don’t even want, multiply themselves twice or thrice every three weeks, and create one of the most balanced, nutrient-rich soil amendments on earth. All life in and above the ground is partly dependent on worms’ ability to transform organic matter into available plant food.

I am a dedicated practitioner of worm wifery, and you can be, too! Here are the basics:

1) A home. Any kind of closed container with good drainage will work. I made one from plywood, but Rubbermaid bins with holes in the bottom work, too.

2) Bedding. Red wigglers need plenty of carbonaceous material to move around in. Shredded paper from the office, a shredded newspaper (after reading it), peat moss, and manure are all good sources of bedding.

3) Moisture. Dry conditions suffocate the worms. If you squeeze the bedding, a little water should drip from your hand.

4) Food. Red Wigglers are mostly vegetarian, and dislike anything acidic like tomatoes and lemons. Occasionally, I throw in some citrus peels and a little leftover cheese because the worms are active enough to eat it up quickly. Like us, worms need carbohydrates. All carbon sources like paper towels, napkins, paper plates, and newspapers go in the worm bin. Crushed egg shells help balance the pH in the bin, and a few handfuls of dirt give the worms grit for their gizzards.

Once all of the essentials are provided, an amazing transformation takes place. A worm bin becomes an entire ecosystem unto itself. I’ve had beetles, springtails, frogs, lizards, spiders, tiny white worms called potworms, and an earthworm or two find their way into my bin. The red wigglers don’t mind the extra boarders. New worm owners are often afraid they might escape out the drainage holes at night, but if the bin is raised off of the ground, the worms will stay in the dark and the moisture. The only reason my worms have fled the coop, so to speak, was because I taped off all the drainage holes in preparation for the moving van (oh yes, my worms have traveled across the country). They must have needed that oxygen, because the next morning, I had little pyramids of worms on the floor, fleeing the sealed bin to catch their breath. I never closed those holes again. To keep critters out, I sometimes put a bit of hardware cloth over them.

It’s easy to take worms for granted. It’s easy, once you have an established bin, to forgot about them completely. But once you have a few thousand of them silently and steadily eating leftovers in your garage or backyard (or inside your coffee table?! Oh yes, it’s been done), their quiet, slow, transformative magic will startle you. Each time I lift the lid of the worm bin and see absolutely no trace of rotten food, only dots of castings scattered across shredded newspaper and clumps of red wigglers hugging food or curled inside eggshells, I am amazed at the absolute transformation. All I needed was a bin, a few worms, shredded paper, and my own food waste for creatures to transform it into the richest plant food on the planet.

Click on the links below to the Tilth Alliance’s worm bin designs. These are the ones I started off withhe plywood bin is for those with access to power tools, or a neighbor’s shop. Mine is still going strong after 20 years!

This “off the shelf” bin is much easier to make. Instead of the “O-ring” and metal valves, and metal vents, I simply drilled holes at the top for ventilation and a larger hole in the bottom for drainage. Tilt the bin towards that hole and place a container under it to catch the worm juice. This has been in my garagin and going strong for 10 years.

Questions? Share them with me! I’m happy to help!

How?

A few years ago, one of our best loved chickens died.  Despite her constant search for a hole in the garden fence, Cacciatore was a wonderful earwig eater and provided our family with beautiful, light brown eggs.  Mom liked having her around while she was weeding, so instead of burying her way out in the field somewhere, I decided to compost her.

Composting farm animals like chickens and cows is a feasible and efficient way to return massive amounts of nutrients to the soil.  “Offal,” as the carcasses of animals are called, is an invaluable resource for composting.  Temperature requirements for this kind of compost are higher and need to be sustained for a longer period of time, which means a lower carbon to nitrogen ratio.  The more nitrogen in the pile, the hotter the pile will be.  Sustaining this heat is the trick.  There needs to be plenty of water and oxygen in order to provide the heat loving bacteria with enough energy and food to keep up the good work.

When I decided to compost Cacciatore, this is what I did.  I gathered all the nitrogen I could find—green grass clippings, kitchen scraps, and chicken manure—and mixed these with bulky carbon material for aeration.  I watered as I worked until the finished pile, about four cubic feet inside strawbale walls, was as wet as a wrung out sponge.  A thick layer of straw served as insulation and discouraged flies.

After two days, the dial on my compost thermometer registered 160 degrees Fahrenheit.  I dug into the center, put Cacciatore in, covered her, and waited.  The pile stayed at 150 for about a week.  I turned it once more in the fall, watering as I worked, and the temperatures rose again to 160 for another week.  Turning the pile twice allowed any material on the edges to have its turn in the hot center.  This ensures that any harmful bacteria or weed seeds all got hot enough to be completely broken down and inert.

I let it sit for a few months until the time came in late summer to move the compost pile into the garden.  With every shovelful, I half expected to see bone, beak, or feather, but crumbly, deep dark humus was all I found.  Cacciatore was finally welcome inside the garden fence.

How does such a complete transformation happen inside such a simple pile of kitchen waste, garden trimmings, and manure?  With the help of billions of microorganisms.  Where on earth will you find these microorganisms to help you transform waste into compost?  Don’t worry, they have already found you.  Just building a compost pile is like lighting a neon sign that buzzes, “Microorganisms Welcome!”

When Carbon and Nitrogen are combined in the right ratio (25 or 30 parts carbon to 1 part nitrogen), when there is enough moisture, some oxygen, and enough mass, the bacteria already found on the waste begin to go to work.

When temperatures are high in a compost pile, anywhere from 130-160, heat loving bacteria (thermophyllic) are hard at work in compost.  On a chilly day you can see the evidence as steam rising from your pile.  Bacteria sweat.  Like us, they burn carbon and release carbon dioxide and water into the air.  They can sustain this work for 3 days to a week, just the right amount of time for many of the pathogens and weed seeds in the middle of the pile to break down (tomato and squash seeds are another story).

Turning the outside of the pile to the inside will ensure that the rest of the pile gets a seat in the middle, too.  You can turn a pile by hand.  If you are lucky enough to have a front loader handy, this is a fast way to turn a large pile on a farm.  Composting in a barrel allows for easy turning either raised on an axel so you can turn it with a handle or just on the ground so you can roll it.  Worms will turn the compost for you (see “worm husbandry”).

When temperatures fall between 80 and 100 degrees, conditions are right for mesophyllic (middle loving) bacteria to explode in numbers.  Now the pile smells “earthy,” like soil. This is the pleasant halitosis of the bacteria actinomycetes (act-tee-no-my-see-tees).  They are breaking down the compost into even tinier particles, and you can see them as white, webby strands throughout the compost pile.

Fungi make their appearance at the very end.  The fruits of their labor bloom as mushrooms on the surface of compost, telling you it will be ready soon.  You will know compost is ready when it smells good, like rich soil, is dark brown, and looks nothing like the slimy, rotten waste it was before.  According to a 1996 article in the New York Times by Nicholas Wade, bacteria “comprise as much as half of all living things on the planet.”  Bacteria are found on almost every surface of the earth, whether internal or external.  Lucky for us, they work to our benefit in compost piles, our stomachs, landfills, wine casks, breweries, forest floors, and sourdough bakeries.  Such a transformation is miraculous, and the end result, humus, is still a mystery to scientists, but there are some things we do know.

We know that humus is the most stable form of plant food available on the earth and can remain in the soil, providing plants with nitrogen, for over 100 years.  We know that over half of the humus on the planet has been lost to over grazing and over working the land.  We know that humus takes a long time to form.  The longer a compost pile cures, the more stable humus you will find.  Like good bread, wine, and beer, it’s worth the wait.  One to two years is a safe bet.  Then it’s time for the compost to return to the garden, the fruit trees, the house plants, and the earth.

Why Compost?

Let’s talk about compost—what it is and why we need to make it happen now more than ever. Every time we eat plants or animals who eat plants, the nutrients they and we need to grow are taken from the soil and put into our bodies for energy. We burn it as energy, but there are always leftovers. Up to 40% of the food grown in the United States is wasted. If these leftovers are not returned to the soil to be recycled, then the cycles that sustain life are broken and things start to get messy.

You’ve probably heard this before, but it’s worth repeating. A handful of compost contains more living organisms than there are people on earth! Our eyes cannot see it, but compost is dynamically alive! The nutrients, minerals, bacteria, fungus, and other microscopic life forms found in compost are vital for healthy soil.

In the United States, we use soil 10 times faster than the natural rate of replenishment, and we only have about 60 years of topsoil left in the world. Such an estimate has to give us pause, and a dose of healthy concern. We need compost in all its forms—backyard piles, turned under cover crops, worm bins, municipal compost operations, forest floors, manure left in the field or composted in the barn, compost toilets (yes, human compost)—and every other way we can think of. We need to balance our soil withdrawals with compost deposits.

This can happen in your own backyard, in a church kitchen, in a community garden, in a garage, and even in an apartment. I’ll discuss how to make compost piles unique to your life style a bit later, but for now I’ll sum up what makes composting work no matter what form it takes. There are 5 keys to creating a healthy compost pile—carbon, nitrogen, water, air, and mass.

1. Carbon and nitrogen are the main ingredients of compost. Vibrant compost piles need a ratio of 20-35 parts carbon to 1 part nitrogen. Carbon, the “brown” materials, are usually brown and dry. Bags of fallen leaves, newspaper, cardboard boxes, paper towels and napkins, wood chips, straw, brown grass clippings, and the morning croissant are all examples of carbon. These are what the compost microorganisms need for sustained energy. Smaller pieces of brown material will break down more quickly because there is more surface area for the microorganisms to work on. Chipping wood or mowing leaves helps to speed up the composting process.

2. Nitrogen, the “green” materials, are usually green and wet. Fresh grass clippings, kitchen scraps, manure of all kinds, coffee grounds, and nutrients like blood and bone meal are all good sources of nitrogen. These will be used by the microorganisms to build their microscopic bodies.

3. A compost pile should be as wet as a wrung out sponge. In order to move, breathe, and function, the microorganisms doing all the work need this water.

4. The microorganisms that break down organic matter also need oxygen. You can compost without oxygen, but it’s smellier. This is called anaerobic composting (more on that later). Making sure the pile has plenty of brown, carbon material to create pockets of air will ensure it has enough oxygen. The pile should be a bit fluffy, like a compost soufflé. As it breaks down, the cake will flatten and reduce in size. This is a good sign.

5. The last key is mass. If it’s not big enough, the compost pile will not be active. A 3’ by 3’ pile is the minimum size for decomposition to really start. But piles built outside need to be at least knee high and wide. You can put your pile inside chicken wire, straw bales, re-used pallets, or even a cheap garbage can buried a foot in the ground with holes drilled into the bottom. For more about how to do this, visit my Ways to Compost.

Way to Compost 1: The Backyard Food Digester

For gardens and people in the city, room and time are big obstacles to composting.  A food digester, sometimes known as a green cone, is perfect if you want to keep organic matter out of your garbage but not work too hard, take up too much space, or think too much about composting it.  Basically, it’s like building a stomach in your backyard that will digest all your leftover food.

Here’s how to do it.  Find an old plastic trash can, or buy a cheap one at the hardware store.  Drill holes all over the bottom and about two feet up the side all the way around for drainage, aeration, and to let the worms in and out. Then, dig a hole so that at least a quarter of the can is in the ground in a shaded, well-hidden place.  This is the only hard labor required.  Put a layer of leaves or small twigs in the bottom of the can.  This is the first layer of your compost “cake.”  From here on out it will go like this:  kitchen scraps, browns (leaves, a little soil, old grass clippings), kitchen scraps, browns, and so on until it is full.

Here’s how the digester system works from kitchen to compost.  Keep a gallon sized, lidded container under the sink to scrape food scraps and vegetable peelings into.  It can be plastic or stainless steel.  Don’t be afraid to put in uneaten mac and cheese, soup, bread, rice, tacos, Fritos—anything you didn’t eat.  And don’t forget that all paper towels, napkins, tea bags, coffee grounds and filters, paper plates, the tubes inside of toilet paper, and newspaper can go in, too.  Carbon sources like these help keep odors at bay (carbon is a great filter) and worms very happy.

Make a trip to the compost container once a week to dump your lidded container.  Be sure to cover it brown stuff—soil, grass clippings, or straw.  You can keep a pile of these brown materials right next to the digester.  I suggest putting on an “inner” lid of pine branches or even a pizza container as well as the trash can lid.  This keeps down smells and reduces fruit flies.  The outer lid should be secured with a bungee cord so little critters like raccoons and rats don’t help themselves.

That’s it!  In about a year with no turning or thinking, the bottom of your bin will be rich compost ready to put around plants in a small garden.  Two digesters side by side is another good idea.  When compost is harvested from the bottom of the first one, the partly digested top material can be shoveled into the bottom of the second one and the process starts over.  Or, you can fill up the first and wait for it all to compost while filling up the second one.

Of course, there will be some troubleshooting.

  1. If the material becomes too dry, it won’t decompose. Be sure to water the digester, especially in the summer, if it is too dry.
  2. Remember to keep a lid on.
  3. Avoid putting meat and dairy in the digester, and bury the food well each time with browns and the inner lid so that maggots and fruit flies will not be a problem. Besides worms, there will be all kinds of bugs in the food digester. It’s a plethora of study material for future entomologists.  Sow bugs, little white springtails, ants, centipedes, beetles, and other kinds of creepy crawlies are harmless and help to break down the organic matter.
  4. If the digester smells (too wet, maybe), mix in soil and carbon sources and it should be better in a couple of days.
  5. You may find vigorous, hybrid varieties of squash and tomato growing where you spread the compost. These seeds persist in this type of composting since there isn’t enough heat to destroy them.

And now for a sneak peak at my backyard food digester, eight years old, quietly working away, mostly forgotten, tucked behind the shed where I hope no one looks. But for you…

Notice three large pinecones–raccoon latrine deterrents (ouch! works great) and weight for lid…a brick or bungee also works…a pile of leaves to layer after dumping kitchen waste…only pistachio shells and pumpken seeds are recognizable. I never turned it or rolled it, only layered it. About once a year, I shovel the finished compost into my wheelbarrow. Looks like it’s time!

One stomach behind the shed is great, two stomachs would be ideal. One to fill again while the full one digests. Don’t you wish you had two stomachs? Now you can!

Composting back to life

Compost connects leftovers to new life

When anything once alive dies and is put in a compost pile, microscopic life forms begin their work of living and dying. They break down organic matter into tinier and tinier pieces, more elemental with each pass through their microscopic bodies. They eat and live and also die, until all that has died becomes entirely new—a particle of nitrogen or carbon, a trace mineral, a salt—so it can be taken up again into plant roots, into animals and human bodies, into trees, then fall back down to the soil as sticks, leaves, bones, and flesh. We label this up and down rhythm life and death—a beginning and then an end. But death it is not the end with compost, rather it is the beginning of something new. I do not completely understand how the transformation happens. Science can explain the invisible process in books, but I go out to the compost pile on a regular basis to observe and maybe absorb a little of the mystery that gives life to our human and earthly bodies.

There is not just one way to compost. It can be done in many ways, and all of them lead to a rich source of life for the soil. I admit that composting is not always fun, like riding a roller coaster or going to a movie is fun. It is not always easy, like throwing away food is easy. It can be mundane, messy, and sometimes annoying. Composting is a mindful act—a decision to humbly take responsibility for our own waste. I found, once I committed myself to it and carved out the time to care for my own waste, that I had invisible helpers. I created a big pile of smelly, clumpy, sloppy waste, but a mysterious collaboration of earthly life transformed it into sweet smelling, crumbly, richly dark humus—the building block of life in the soil. I also noticed that I was more forgiving of my own “garbage.” My life’s leftovers—the sadness and pain I usually put a lid on and never wanted to deal with—were uncovered, held, observed, and worked into my life with love. I began to feel more whole.

I invite you into the messy, mundane, mysterious, and restorative life of compost.

Who?

Do you remember the film the series “Planet Earth?” New technology allowed them to zoom in from tremendous distances with crystal clear clarity.  Such groundbreaking camera work is not only visually stunning, but scientifically important in studying the behavior of animals while unaware of a human presence.  The series included, “Deserts,” “Ice Worlds,” “Great Plains,” “Caves,” and “Mountains,” but missed one of the largest, most fascinating, and crucial parts of our interconnected planet—the soil.  So, for the next few paragraphs, let’s take a close look at what we walk on every day.

First, “Soils” takes you to view the largest and heaviest living organism in the world.  Not the Pacific Ocean’s Blue Whale or newly discovered Giant Squid, but Eastern Oregon’s honey mushroom.  The fungus Armillaria has been growing in the Blue Mountains for over 2,400 years.  The mushrooms above ground are only the fruiting bodies of this giant.  Below ground, its white filaments, or mycelia, spread over 2,000 acres, penetrating the roots of trees and siphoning off water and carbohydrates.

In this same forest, a rare, slow motion shot captures the dramatic flight of a springtail. The almost transparent arthropod uses its well-developed mandible to graze on fungus at the base of a tree.  Suddenly, its arch-enemy approaches—a small ant with a strange, spongy structure between its thorax and abdomen that emits an irresistible odor.  Stinger ready, the ant moves closer, but the springtail comes to its senses just in time.  It releases a catapulting organ tucked under its abdomen and springs twenty times its own length to safety.

The camera follows the baffled ant as it scurries down into the leaf litter.  It is a quiet, moonlit night, and the soil surface comes alive. A night crawler waves a third of its body above the ground in an eery, graceful dance.  It finds a leaf and pulls it down into a vertical burrow lined with its own mucous.

Not too far away is a colony of several million ants.  These particular ants practice aphid husbandry.  They faithfully transport aphid eggs to their nests each autumn, tend them in safety, then take the newly hatched aphids to fresh, spring roots.  As a reward, adult aphids leave their sugary droppings, called honeydew, as food for the ants.

Finally, “Soils” films the strange and captivating Tardigrade, or “Water Bear.”*  Just as the Polar Bear elicits “oohs” and “aahs” with its antics on the ice, so the tiny Water Bear, only 1/50 of an inch long, is the charmer of soil critters. They come in red, green, orange, yellow, and pink, and their eight legs each end in four tiny claws.  Their eggs, spheres decorated with geometrically patterned spines, knobs, and ridges, are fascinating and beautiful.  If the humidity level in their microscopic habitat drops, they shrink like a dry sponge into an unrecognizable form. In this state, they can survive temperatures up to the boiling point and down to -200 degrees F.  Then, even after 120 years, the dehydrated Tardigrade can be brought back to life.  Some scientists are studying this amazing feat of cryptobiosis (hidden life) to see if humans could do the same.

Here’s one of the coolest videos I’ve ever seen on tardigrades!

And this is just the beginning.  There are thousands of animals and insects that live in symbiosis and competition under the soil—from Ant Lions to Glowworms, from Camel Crickets to Kangaroo Rats.  Without them, life above the soil would come to a messy halt.   Soil creatures take the minerals and nutrients that drop to the ground from above and incorporate them into the earth’s skin where they resurface as new plant and animal life.

In order to better understand the soil and critters that inhabit the soil, all you have to do is build a compost pile and observe it closely.  Ants, springtails, worms, beetles, and maybe even a Tardigrade will appear to transform your detritus. If you would like to see pictures of all of these creatures, check out the book “The World Beneath Our Feet: A Guide to Life in the Soil” by James B. Nardi, and watch the movie, “Microcosms,” a documentary set to classical music depicting the wonder filled life of insects.

*The drawing of the water bear for this post is from the DataBase Center for Life Science (DBCLS) – https://doi.org/10.7875/togopic.2017.5, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=57116616.