Monday, July 28, 2014

Compost: How to make it

Our lovely compost bowl.
Second in a series on compost - what it is, how to do it, and how to use it. A special entry for urban growers will also be included along with a list of further resources.

Compost usually begins in the kitchen. A bowl lined with newspaper (carbon) gets filled up with vegetable an fruit scraps (nitrogen). This in turn gets transferred to a bucket also lined with newspaper on the porch. The newspaper provides carbon, but it helps absorb liquids, which keeps the bucket and bowl relatively tidy. The bowl is turned upside down to empty it and the newspaper lands on top to make a nice lid. This hides it from the watchful eye of our neighborhood crows and makes it less shocking for visitors.

The bucket in turn gets transferred to a bin near the garden. In Tokyo, my two bins were made of chicken wire and poles, which allowed air and water to move through freely. In Michigan, the bins were made of old pallets, which also allowed air and water to move through freely. Water and air are pivotal for the assorted creatures that will be crafting the compost. Water helps them travel within the pile and keeps them alive, just as it does the plants and the gardener, so they can do their work. Air, of course, is what these creatures breathe. Carbon - newspaper, leaves, twigs, cardboard, etc. - also helps with air and water flow in the pile. These chunkier items then create little pockets that allow creatures move about as they snack, but also allows them to find the oxygen and water they need to survive.

In Japan, round plastic green bins with lids are popular compost bins. These are tidy and attractive and relatively effective; however, their biggest problem is the lid. Water and air, as mentioned above, crucial for the survival of the decomposers, cannot enter if that tight-fitting lid is in place. Neighbors and gardeners alike worry about the contents getting smelly or attracting animals; however, a healthy, active compost bin shouldn’t smell. If their isn’t enough air and water, the activity becomes anaerobic. Decomposition will still occur, but alcohols (of which, according to Lowenfels and Lewis, one part per million will kill plant cells) will be produced. Take the lid off.

Animals may come, but in my experience in rural Michigan, Tokyo, and now Kanagawa, they have not been a problem. If the bin is smelly, animals will be attracted; however, most of them eat in place. Pigeons and other birds frolic and nibble, tamping down the contents and adding their digestive process to the contents. Other creatures may come, but they won’t stay. The garden and bin will be relatively active places, which makes them unattractive homes. If decomposition is going well, the pile should be too hot for comfortable living.

Next: How to use compost
Previous: Compost defined


Bonolo said...

hi, there

where can I find a good composting bin for a flat in Chubu?


Joan Lambert Bailey said...

Hi Bonolo,

I might suggest contacting James Kemp at Japan's branch of Can O'Worms. Here is their website: our local website:

It is all in Japanese, but if you contact them directly you'll be in business. James is also quite knowledgeable and will help you get things rolling.

Unknown said...

Hi Joan! Do you know any place in Tokyo where I can drop off my organic scraps for composting?

Joan Lambert Bailey said...

Hi Rachel, I am sorry to say that I do not, although it may depend on where you live in Tokyo. If there is a farm near you, they may be willing to take your scraps and add them to their heap. It may also be possible to get/make a home composter, too. There are Bokashi composters at home centers, and there is a worm composter available from the Worm Guy. Let me know how it goes!