Way to Compost 1: The Backyard Food Digester

For gardens and people in the city, room and time are big obstacles to composting.  A food digester, sometimes known as a green cone, is perfect if you want to keep organic matter out of your garbage but not work too hard, take up too much space, or think too much about composting it.  Basically, it’s like building a stomach in your backyard that will digest all your leftover food.

Here’s how to do it.  Find an old plastic trash can, or buy a cheap one at the hardware store.  Drill holes all over the bottom and about two feet up the side all the way around for drainage, aeration, and to let the worms in and out. Then, dig a hole so that at least a quarter of the can is in the ground in a shaded, well-hidden place.  This is the only hard labor required.  Put a layer of leaves or small twigs in the bottom of the can.  This is the first layer of your compost “cake.”  From here on out it will go like this:  kitchen scraps, browns (leaves, a little soil, old grass clippings), kitchen scraps, browns, and so on until it is full.

Here’s how the digester system works from kitchen to compost.  Keep a gallon sized, lidded container under the sink to scrape food scraps and vegetable peelings into.  It can be plastic or stainless steel.  Don’t be afraid to put in uneaten mac and cheese, soup, bread, rice, tacos, Fritos—anything you didn’t eat.  And don’t forget that all paper towels, napkins, tea bags, coffee grounds and filters, paper plates, the tubes inside of toilet paper, and newspaper can go in, too.  Carbon sources like these help keep odors at bay (carbon is a great filter) and worms very happy.

Make a trip to the compost container once a week to dump your lidded container.  Be sure to cover it brown stuff—soil, grass clippings, or straw.  You can keep a pile of these brown materials right next to the digester.  I suggest putting on an “inner” lid of pine branches or even a pizza container as well as the trash can lid.  This keeps down smells and reduces fruit flies.  The out lid should be secured with a bungee cord so little critters like raccoons and rats don’t help themselves.

That’s it!  In about a year with no turning or thinking, the bottom of your bin will be rich compost ready to put around plants in a small garden.  Two digesters side by side is another good idea.  When compost is harvested from the bottom of the first one, the partly digested top material can be shoveled into the bottom of the second one and the process starts over.  Or, you can fill up the first and wait for it all to compost while filling up the second one.

Of course, there will be some troubleshooting.

  1. If the material becomes too dry, it won’t decompose. Be sure to water the digester, especially in the summer, if it is too dry.
  2. Remember to keep a lid on.
  3. Avoid putting meat and dairy in the digester, and bury the food well each time with browns and the inner lied so that maggots and fruit flies will not be a problem. Besides worms, there will be all kinds of bugs in the food digester. It’s a plethora of study material for future entomologists.  Sow bugs, little white springtails, ants, centipedes, beetles, and other kinds of creepy crawlies are harmless and help to break down the organic matter.
  4. If the digester smells (too wet, maybe), mix in soil and carbon sources and it should be better in a couple of days.
  5. You may find vigorous, hybrid varieties of squash and tomato growing where you spread the compost. These seeds persist in this type of composting since there isn’t enough heat to destroy them.