I refer to composting a lot in this blog, but only until recently, prompted by a reader, did I realize that I haven’t yet given any practical information about composting. Now that we’re heading into summer, a composting step-by-step is in order.
First, a little background: Growing up, I knew about composting as the semi-secretive operation that my father carried out on an overgrown strip of land to the side of our driveway. It was possibly an eyesore to the neighbors, but fortunately these were pre-Martha Stewart Living days and they didn’t complain. From time to time, I also leafed through a very ’70s-style book called Mulch that my father thoughtfully kept on a shelf in the bathroom (along with a variety of other garden literature). That was the extent of my knowledge and participation in composting.
About a year ago, I felt it was necessary to confront the old pile. By then, my father the gardener was no longer around to ask, but I’d become a composter in my own right and was curious about what my father’s work had produced. The first part of the journey into the depths of the pile was nightmarish. He had secured a seemingly indestructible plastic enclosure with metal stakes, now rusted. After a trip to the emergency room, so my husband, who was helping me, could receive a tetanus shot, we proceeded to detach a network of vines and tree roots that grew over and around and through the pile. In the end, I did get a little of what I was looking for: rich, crumbly humus that I put to use right away around newly planted shrubs. And the importance of pile placement was brought home to me. Trees and vines are opportunistic. They had been feeding on that pile for several decades. Some vine control earlier on would have left us more of the good stuff.
I bring up this story partly to illustrate that there are many ways to compost and what works best has much to do with the kind of gardening you do, what kind of space—and how much of
it—you have, and what materials you are planning to compost.
The guide that follows is based on the three-bin composting system for food waste that I set up at the Clinton Community Garden. It’s easily adaptable to a backyard garden.
Finding a space for your bin or bins: Well-managed compost does not stink, but it’s still better to place it in a low-traffic area, away from patios, windows, and curious kids and pets. Extreme shade, sun, and moisture are not ideal, but there are ways to work around those conditions if necessary. Bare earth, as opposed to pavement, is nice to have, but many urban gardeners, whose backyards are courtyards or balconies or rooftops, don’t have access to the ground. No matter, compost will still happen in the right kind of container (I will report on this soon in another post).
Preparing the space: Clear away plants from the spot you’ve chosen and smooth out the ground. If you have trouble with rats or mice, you can rodent proof your composting area with hardware cloth, a heavy wire mesh. Use hardware cloth with quarter-inch holes. Lay the cloth on the ground and stake it in place. The bins will sit on top and should also be staked in (I’ll explain further on).
What bins to use and how many: I’ve had good luck with Garden Gourmet composting bins. If you have a little extra space to accommodate a round shape, Earth Machines are lower to the ground and broader at the base, which is helpful both for aeration and turning the compost. At the garden, I placed three bins side by side against a shed wall. A single bin might be enough for one household. The advantage to having two or more is that composting can continue after one bin is closed off for “cooking.”
Securing the bins: Garden Gourmets come with plastic anchor stakes, but I found these didn’t last long. To keep the bins in place, I used long coated metal planting stakes (slightly less than a quarter inch in diameter), which I cut to fit and ran down through each corner of the bins. These stakes also help retain the shape of the bins, which are made of recycled plastic and benefit from some extra structural support over time. To further discourage rodents and weigh down the hardware cloth, I filled in the spaces surrounding the bins with gravel and broken bricks.
Now the bins are ready to receive food scraps and garden waste. At my garden, we compost food waste and garden debris in separate bins. We have so much garden waste that it would quickly overwhelm the Garden Gourmets, so vegetation is corralled in a large open bin where it breaks down over the course of a summer. In the enclosed bins, food waste decomposes rapidly and compost can often be harvested a few times over the summer.
What to compost:
- fruit & veggie scraps (peels, skins, cobs, pits)*
- egg shells
- loose tea and tea bags
- coffee grounds and paper filters
- nut shells
- food-soiled paper napkins
*For best results, chop up food scraps in your kitchen with a sharp knife before adding them to the compost bin.
What not to compost:
- dairy products
- meat and bones
- animal litter
- bread, cooked and uncooked grains, baked goods
- liquified, slimy organic matter
- compostable or biodegradable bags—they turn into a goopy substance
Layering is the preferred method for adding material to the compost bin. By alternating layers of “greens” and “browns,” you can balance nitrogen-rich material with carbon-rich material. Food waste and fresh green garden waste, like cut grass, is high in nitrogen and water. Dry leaves, newspaper, cardboard, and saw dust from untreated wood are all good sources of carbon. The recommended carbon to nitrogen ratio is 30:1, which may sound off-puttingly specific. Composters learn to eyeball it. For instance, for every new deposit of kitchen scraps, I add a layer of browns that’s about twice as thick. It also helps to dig into the pile before adding fresh material. I know when my calculations are a little off and the bin is too wet (the most common situation) because it will give off a slightly sour ammonia smell. The fix is to aerate the pile by digging and turning the material and adding more dry ingredients (shredded newspaper and dry leaves are the best for this). You will want to keep a container of browns nearby. Turning the bin once a week will speed along the process and keep all the bin inhabitants (the decomposers, the chewers, the tunnelers, and the diggers) active and happy.
Tools and materials:
Pitchfork, shovel, gloves, sifter, wheelbarrow, compost crank, hardware cloth, and bins
Garden Gourmet compost bins:
If you live in NYC, visit the Lower Eastside Ecology Center for discounted bins (http://www.lesecologycenter.org). You can order them and then pick them up at the Union Square Farmer’s Market.