make your own: indoor compost bin.

We’ve had a cardboard banker’s box full of compost underneath our couch for the past month. A few times a day, or any time we add fresh scraps, we turn the rich dark brown mixture with a trowel. When we do, it smells of clean earth and, vaguely, a fire pit. The rest of the time it sits unassumingly under the couch in the middle of our apartment, calling exactly zero attention to itself as it steadily disappears our family’s food and flower scraps.

At the beginning of May, New York City stopped its curbside organics collection and cut funding for community composting programs across the city for at least the next year. It’s a shortsighted austerity measure made in the midst of the covid-19 pandemic and it has the potential to undo years of environmental progress. In that first week, Hiroko Tabuchi, climate reporter at the New York Times, published a piece detailing how, for the past seven years, she’s lived with an odorless compost box beside her couch.

In her piece, Hiroko explains that the method—mixing food scraps into a combination of ash and coconut peat inside a simple cardboard box—is common in Japan, but virtually unheard of in the U.S. Don’t waste any time on incredulity regarding keeping compost in the living room, this method isn’t just cheap and brilliant, it’s tried and tested.

I followed the instructions from the original story and was helped along by these visuals and the Cardboard Box Composting Google Doc that Hiroko created as a follow-up. Among many other helpful details, the Google doc includes a list of all of the kinds of food scraps that can be composted using this method (for us that includes the vast majority of the scraps we end up with). Below are few specific materials that I used to build my box, plus a few tips that have been helpful for me.

Materials:

+ A cardboard banker’s box with lid (I got mine from a neighbor through the Buy Nothing Project.)

+ Extra cardboard to reinforce the bottom of the box

+ ~ 1.5 pounds of coco peat (I weighed it before reconstituting with water. I wasn’t sure if that was the right move, but’s worked perfectly so far.) (At the time when I bought mine, I could only find a large block, so I shared what I couldn’t use with neighbors. If you’re looking for your own supplies, Natty Gardens is a black-owned nursery and gardening supply shop in Brooklyn that carries coco peat blocks.)

+ 1 pound of biochar

+ 1-inch x 1-inch square dowel cut into 12-inch lengths; purchased and cut to size at the local hardware store

+ 4 screws (and a drill)

+ 4 felt pads

+ A sturdy garden trowel for breaking up the scraps and mixing the compost

Tips:

+ I generally chop any larger food scraps into smaller pieces before adding them to the mixture and I keep my trowel in the box with the compost to mix and further break apart any new scraps.

+ In the first week or so, I found my compost mixture was becoming too dry, too fast, so I often added water until I noticed it stopped drying out. (The coco peat is exceptionally absorbent, so my box has stayed totally dry.)

+ To keep air flowing around the cardboard box, it needs to be propped on wooden blocks. These can definitely be pieces of scrap wood, but I wanted to keep the bin as neat and simple for the whole family to use as possible, so I made a small wooden frame from square dowels and adhered felt chair pads to the bottom of it so we could easily slide the box out from under the couch when we add more scraps.

+ With the exception of items not recommended, we add most of our daily food scraps to our box. The compost grows very slowly and does an excellent job of breaking down a relatively robust quantity of daily scraps (we’ve been following the guideline of adding roughly 1.5 pounds of scraps each day). For reference on volume, the above photo shows the mixture before any scraps were added and the first two images of this post show the box as it looks today, after more than a month of adding scraps daily. As you’ll see, the volume is pretty nearly the same.

Action items:

+ Our compost box has been a really successful experiment for our own family, but it doesn’t begin to replace the infrastructure and support, to say nothing of the impact, of a city funded program. In New York City, the city’s budget could be finalized by the end of this week. It’s crucial that New Yorkers make their budget concerns known and ask that at least a portion of the budget for composting be reinstated. Follow Save Our Compost and Big Reuse for daily action items including email templates, talking points, phone numbers etc. needed to make your voice heard.

Other things:

+ For anyone looking to read more about the links between racism and environmental degradation, this reading list by Somini Sengupta for the New York Times is a good place to start.