Three-bin compost system

We are making use of the winter months to tidy up the community garden and doing maintenance work. Last week we sorted out our compost bins, which have been annoying me for a while.

Our original plan was to have three compost bins, as per traditional gardening wisdom. However, our recycled window greenhouse got in the way of the third bin, so we have been living with two bins for the last couple of years. It has worked OK, but not to full composting efficiency. And so finally we put it right…

The theory with three compost bins is that you put your compost ingredients into the first bin (annual weeds, vegetable peelings, paper, etc..). When that is full, you turn it into the second bin, and continue putting new compost into the first bin. When the first bin is full again, you turn the compost from the second into the third, and from the first into the second. With me so far?

Once you have that up and running, you have a continuous production of compost, with ready-to-use compost in the third bin, and just-starting compost in the first bin.

Turning the compost from one bin to the next gets the compost mixed up, so the partly decomposed gets mixed up with the not-so-decomposed. But more importantly, it introduces air, a necessary component of aerobic decomposition. No air means anaerobic decomposition, which = smelly!

The problem with our two-bin system was that when our first bin was full the compost from the second bin wasn’t quite ready to use, but we didn’t really have anywhere store it.

So… making use of the quieter months, we spent our recent work day relocating the compost bins (and compost!) to the opposite site of the plot, where there was room for three. And now we have a bit more space in between the shed and greenhouse for storing miscellaneous bits and pieces we have accumulated that were taking up room on the patio!

The bins are a combination of pallets from the local builders merchant and ex-floor boards. The front boards sit in a groove and they slide out for easy removal of compost.