Way to Compost 4: The Barrel or Compost Tumbler

We bought our first house nine years ago (still here!), and the first thing I looked for was a place to build our compost pile. I found a nice, hidden corner for the food digester and a spot under the two hackberry trees in the back for a version of the 3 bin system. But it would be a year before compost was ready, and I needed some now! I was planting a garden soon and had none of the humus-rich, wonderfully textured stuff to fork into the soil before planting. My worm bin was humming along in the garage (we moved it with us, worms and all, and we’d never had a garage before), but it did not produce enough compost for even 50 square feet of a garden.

Our food digester and leaf pile tucked between fence, wild cherry, and old playground ball

The appeal of the barrel system is speed, and that turning it is as easy as turning a handle. Barrel composters often sit up off of the ground on a frame with a handle that turns a paddle inside of the barrel to mix up the browns and greens into compost. Other designs allow you to turn the entire barrel, rather than having a paddle and axle inside. I had a friend who had his barrel on the ground. He added materials to it as needed and simply rolled it on the ground about once a week. Because it was on the ground, red wigglers found their way in and helped out.

A quick search on the internet led me to Ms. Tumbles, but there are lots of ways to acquire your own tumbler. You can build one, grab an old garbage can with lid and roll it around, or buy one.

Like all successful compost piles, a barrel composter will need both brown and green materials, moisture, oxygen, and mass. If you can provide all of the necessary ingredients in the right ratios, it can work just as well as a hot compost pile. If your barrel is up off of the ground, critters won’t be able to access it as easily, a bonus for those in the city.

Side note: Just last week I watched a healthy looking skunk emerge from beneath our neighbor’s old garage that sits along our property. It waddled along the fence, taking a detour under the trampoline, brushing past the now blooming comfrey, and stepped right up to her breakfast of compost. While I’m not too worried about this (gasp!), others may not be as welcoming to critters, so a barrel is perfect. Contained, up high, skunk proof.

Photo by Tom Friedel: https://commons.wikimedia.org/wiki/File:Striped_Skunk.jpg

Turning it is also easy, and you won’t need to get out the shovel every few weeks. Barrels fit well in a smaller yard much better than a three bin system can, and for those who like a tidy garden, it looks just that, neat and tidy. This is a good option for those who do not have time to make and turn a pile, have little room in the backyard, and want compost fairly quickly.

Here’s the thing, though. Barrel composters often claim to provide compost in just a couple of weeks. But like good wine, good compost takes attention to detail and time to cure. You might get compost in three days to two weeks, but it will not be as humus rich as piles that cure for a year or more.

Slicing into this one year old pile is like cutting into a humus cake, full of richness for the soil, frosted with fall leaves

Humus is garden gold. It is the final result of decaying plant and animal matter, whether in a forest or your compost pile. As your leftovers break down further and further, they get down to their most elemental selves, a negatively charged humus particle. Think of humus as a plant buffet—the most stable form of plant food on the planet. Briefly, humus holds minerals, nutrients, and nitrogen in the soil so they don’t leach away. When plant roots come into contact with humus, they exchange their positive ions for the negatively charged food they need to grow—phosphorous, calcium, nitrogen. Humus also gives the soil more water and oxygen holding capacity by becoming a kind of sponge.

Humus is the casserole of the soil: spongy, generous, something for everyone.

Humus is in sharp decline. Modern farm methods need crops in quick succession. Instead of adding organic matter in the form of cover crops and letting the soil rest and regain its humus for the next crop, we add synthetic fertilizers that tend to be over applied and leach away into our water systems. Fertilizer cannot create the kind of tilth, the crumbly, dark, sweet-smelling soil, that humus creates. They are a quick, chemical fix to a deep and long-term humus shortage.

Not to despair! The answer to our humus shortage is staring us in the face, on our dining room tables, right at our fingertips. We can save humus with everything we throw away. Humus is created through decomposing organic matter, organic matter that Americans have an abundance of. Millions of tons of organic matter is sent to landfills each year where it creates methane, a greenhouse gas more powerful than carbon dioxide, instead of humus, the very thing we need to replenish the soil. Cities like Seattle, New York, and Portland, OR are beginning to divert organic waste to compost facilities in large numbers, but we need more cities on board. Some European cities even use anaerobic composting (without air), biodigesters, to create energy from decomposing food waste. Digging through compost history, I discovered a woman scientist from Germany hired to design and install biodigesters for Mexico, turning their organic waste into energy, in the 1950’s! We are just beginning and at last learning from, as Janine Benyus calls them, “our wild teachers” and “nature’s genius.” Just like in nature, when we compost, nothing is wasted, everything can be recycled.

The one becomes the other, and the other becomes the one, in a reciprocal song that changes key now and then, but can keep making music forever.

Leftovers are not waste, they are opportunity. An opportunity to heal the soil, mitigate climate change, and grow beautiful crops, flowers, and trees. To some, putting leftovers in a barrel and turning it might sound as crazy as getting in one and riding it over the edge of Niagara Falls, but compost barrels are just as thrilling for the worms, bacteria, and fungi inside, tumbling your compost into a national treasure waiting to be buried and brought back to life.