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!


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.