Over the weekend I built a three-bin composting system.

Unlike my usual projects, this time I (mostly) followed someone else’s design, specifically one I found from the University of Missouri Extension.

The idea of the three-bin system is that you add compostable materials to one bin, then when that’s full you transfer the material to the next bin, then later to the third bin. Each time it is transferred, it gets turned over, and each successive bin has hotter microbial activity, breaking down the material more and more.

We already had a three-bin system with plastic bins, but they were overflowing, and not used properly, being harder to access:

So I wanted to build new larger bins, using a design that is easier to access.

To start, I made four frames out of treated wood (check out the design above for dimensions and such if you want to build this yourself):

Then added hardware cloth on the frames:

The frames were arranged and connected by a couple of 9’ treated boards; these will be on the bottom:

A similar connector on the top:

Hardware cloth on the back:

Runners on the front:

Creating a pair of slots for each bin:

Which are filled with slats; these can be easily removed to access the compost:

Lid frame (different than their design):

Hardware cloth on the lids:

Once complete, I transported it from the workshop on a hand cart:

Roughly placed near the old bins:

In position; I decided to keep the old compost bins for extra capacity, since there’s plenty of space:

I shoveled the overflow from in front of the old bins into the center bin (since it is already partially composted). I’ll add new material in the right-hand new bin (being closer to the chicken coop):

New and old:

Compost:

Bert enjoyed investigating where the overflow pile was:

I added hinges (I didn’t add them in the shop to leave the lids off to reduce the transport weight):

Done:

Again, I can’t take any credit for this design, but I think these will work very well, and give us plenty of room for composting.