The 3-bin compost system involves either building (or buying) 3 linked “bins” or boxes. This method is best for gardeners who have the ability to easily turn compost with a pitchfork, and for larger gardens that produce high amounts of plant and food waste.
You will start by adding your first compost materials to the leftmost one, layering browns and greens and turning once or twice a week, just like with other composting methods. After it has begun decomposing and you have a pile that is around 3x3x4’, you will rotate the first pile to the second bin and add more material to the first, and so on. Once each bin is full, the first bin will be your add-to pile, the second will be your closed compost that is curing, and the third bin will be your finished product.
Once you’ve used up your finished compost, you can start all over again. At every stage, you can use a pitchfork to turn the piles, but this will be more physically demanding than other systems like the vertical composter.
This tutorial takes you through how to build your own simple 3-bin system from used (non-treated!) wood pallets. If you opt to buy one, keep in mind that this will be more expensive.
If you need a refresher on the basics of compost, use our post on Composting 101 and this infographic to help get up to speed.
Here are some things to keep in mind about composting using a 3-bin system:
- You will need to be especially vigilant about weed seeds getting into this system and weeds growing around it, since you won’t be able to move it once you’ve started, and the compost will be sitting directly on the ground.
- You may want to put a pallet over each of these bins to keep moisture out if you live in areas with wetter climates. If you do so, it is important that you leave the bins opened on the side so you can get in and turn or shovel out the compost in them (some designs add a pallet to make a box rather than a simple three-sided area).