How a Three-Tier Compost Bin Works
All your dead leaves, grass clippings, twigs, hay, and kitchen food scraps (yes, even meat scraps and bones are fine, as you'll be working on a one-year system with your dirt) get tossed into the first section of your compost bin until it's a full, big pile. When that bin is full, you shovel it all into the second bin (top-to-bottom). Then you go back to filling the first section of your compost bin. When it fills up again, you move everything from compartment 2 to 3, and from 1 to 2. Then you start over. When all three compartments are full (this should take the average household a full year or even longer), the third bin should be ready to be shoveled out into your garden.
How it works is that over time, the materials in each bin will be decomposing. The process is sped up by your twice-yearly aeration (manually shoveling the pile into the next bin), rainwater falling from overhead, and the natural aeration that will occur by oxygen reaching your pile from the nice big spaces between the wood of the pallets. Also, because you're leaving a bare earth floor, worms and other bugs have easy access to your compost heap.
Click here for tons of really great compost information.
If you're worried about backyard pests like raccoons or coyotes, be sure to install a hinged door on the front three sections of your compost bin. And of course, if you live in suburbs or the city, you may be subject to zoning or community board laws that would require a closed compost container such as a tumbler. For the rest of you, here's how to have your own three-tier compost bin in fewer than 15 minutes and for just the cost of screws.
What You'll Need:
- Pallets (12 feet of pallets for back wall, four 4-foot pallets for the walls. Check with your local hardware store, contractors, big box stores, or your local transfer station. Free pallets are in abundance!)
- Galvanized Decking Screws (longer is better)
- Optional: Three "front doors" for your compost sections with hinges (each door should measure 4x4)
- Screw the far left wall into the back wall with screws every six inches or so, driven from back to front.
- Repeat with the second wall (if pallet is wide enough, screw it into both sections of back wall. If not, you may need some additional pieces of wood to create a solid back to screw into. We were fortunate enough to find a very long pallet to have one continuous back wall). Continue until you have four walls and one solid back wall. Refer to photo at top of this post.