A report on progress with composting here in Brookland (DC) in one of the city SuperCans:
A bit under 2 years ago, I decided to turn a somewhat-unused extra green DC supercan into a compost bin. I used a spade bit to drill a whole lot of 3/4″ diameter holes all over the sides and bottom of the plastic bin, and began tossing our food scraps, coffee grounds, yard waste, and even used kitty litter.
(More on that in a bit.)
At first I tried to layer things: a layer of grass clippings, then kitchen scraps, then cat poop & pee, then yard waste, then ashes from the grill, then more kitchen scraps, a little ordinary dirt (to add fungi, soil bacteria, nd so on to help decompose everything). More recently, we just throw in whatever we think will break down easily. We have too much yard waste to fit, and so do many of our neighbors, but we are lucky enough to know of a place not too far away where we can put large piles of weeds, etc, where it blends in to the wilds of the neighborhood, doesn’t attract vermin, and slowly breaks down into wonderful compost — eventually. Every week or so, one or more of us go through the area and pick out fast-food bags and wrappers and various cans and bottles of all sorts that local motorists throw there. There are different sorts of trash!
At one point I even spent about $30-$40 for a shipment of worms to help break things down. Result: total failure. Proposed reason: wrong species of worms, and bin too dry and/or cold during the winter.
A few conclusions:
1. Make sure any yard waste is broken or cut up into small pieces. Branches that are more than a centimeter thick (say, 1/2″) will take a very long time to decompose.
2. Don’t bother with worms. Unless you really analyze the needs of the many species of worm, they will die out and burn a hole in your wallet. (Silly me! I thought there were only a few species of earthworm – nooo!)
3. Add local topsoil every so often, especially at the beginning. Much like with sourdough bread, you have to acquire the right mix of microbes to do their digestive and fermentatory wonders on your compost. Your local topsoil is probably the best and cheapest place to find it.
4. Don’t put in cat pee chunks of kitty litter. While cat poop decomposes quite quickly, the clumping kitty-litter which holds vast quantities of cat urine does NOT. It stays as a little nasty ball almost forever. Obviously your call on whether you want to add pet feces at all. I’m not going to do so any more. I say that composting cat waste smells less bad than said cat waste in reused plastic grocery or newspaper bags, sitting in the ordinary supercan. My wife argues the opposite.
5. Keep the mix moist enough to break down (using a hose), but not wet enough to be waterlogged (that’s why you need holes at the very bottom of the bin).
6. If it’s waterlogged, then anaerobic bacteria & fungi take over, and they tend to stink really badly. Aerobic stuff doesn’t smell bad. If the mix is just right, then it will be warm to the touch and will smell sweet. (But then again, I was in fact raised near a cow barn and chicken shed in far Montgomery County, so my opinion probably doesn’t count.)
7. Every 6 months or so, you dump it out and sort it. I made a screen much like the one you see interns using on archaeology or anthropology digs, with 1/2-inch diameter ‘hardware cloth’ and some two-by-fours, screws, staples, reinforcements, and thin plywood scraps. Without a screen like that, it’s not a pleasant job. With the screen, it’s slightly satisfying. Whatever goes through the screen gets added to a garden. Whatever doesn’t, goes back into the bin or elsewhere.
8. Does it save money? Heck, no. A couple of bags of LeafGro compost from Montgomery County cost less than $10, but it is satisfying to know that most of my kitchen waste is eventually going onto our gardens instead of a ‘transfer station’ and dump.
9. Does it cut down on the trash flow to the municipal dump? Certainly, at least from my household.
10. Do I recommend it for everybody? Again, no. On the other hand, it would make sense for DC to do like Oakland CA does: there is a THIRD set of trash cans to collect stuff that will decompose — i.e., yard waste and kitchen scraps, even paper wrappers. There in CA they sell the stuff to farmers in the Central Valley. Here in DC, instead, we simply put all such waste, along with mattresses, building materials, plastic bags, and so on into a ‘sanitary landfill’ where it is preserved for future archeaologists and miners to sift through. I hope our descendants appreciate all the care we took in fossilizing our kitchen scraps, tree stumps, pet poop, and raked-up leaves so they could examine our private habits in the year 2345!
Guy Brandenburg, Washington, DC