How to Build a Compost Pile
Find a Location for the Pile
Your pile can be built anywhere except up against a structure such as a house or fence. Macro organisms (bugs, etc.) will assist you in the composting process. You want them in the pile, not in the house. Locate your pile at least 2 feet from any structure.
Set up a Compost Bin (Optional)
A bin is unnecessary. You can just build your pile on the ground. However, bins are useful for keeping your pile looking neat, retaining heat and moisture, and avoiding the negative effects of wind and weather. If you live in a rural area where food wastes are composted in your pile, a bin can help deter pests.
Prepare the Materials (Optional)
Ensure you have both greens–nitrogen (grass, manure) and browns–carbons (leaves, dried hay) available, and shred carbons that are more than 1–2″ in size.
Build the Pile
You may simply throw in organic materials as they become available. This will result in a very slow decomposition process, but may be appropriate if you are not in need of the finished compost.
If you are building a pile using the batch process for faster decomposition, follow these steps:
- Wet the ground under the pile.
- Put Twigs or other unshredded carbon on the bottom of the pile to provide some aeration at the base.
- Layer the rest of your materials, alternating nitrogen and carbon layers. Add water as you go.
- End with a carbon layer.
Cover the Pile (Optional)
Experts disagree on whether a cover is necessary. If you live in a region that is excessively dry or excessively wet, cover the pile with a black plastic garbage bag to retain moisture or guard against rain.
Monitor the Pile (Optional)
Check to see that your pile becomes hot within a few days. The pile’s heat should peak again after turning. After that, it should peak again every time you turn it, although the peak temperature will be lower and lower with each turn. Also monitor the moisture content of your pile. When you pick up a handful of material, it should feel like a wrung-out sponge.
Turn the Pile (Optional)
Turning the pile means stirring it up by some method. Turn the pile to decrease composting time. Turning the pile allows all the material to be exposed to the hot center and increases aeration.
When is Compost Finished?
The finished compost will take up only 25–40% of the space occupied by the original pile. When the individual materials can no longer be identified and the pile resembles dark rich soil, the compost is completed. It will smell sweet, woodsy, and earthy. It will crumble through your fingers.
From beginning to end, the composting process can take from 6 weeks to 2 years. Hot composting times will be much less than cold. Everything matters—how often the pile is turned, what materials went into the pile, the condition of the materials, moisture, adequate air, presence of insulation around the pile, size of the pile, etc. If you add materials as you get them, instead of building batches of compost, you will find that after 6 months to two years, the inside and bottom if the pile, i.e., the matter you added first, has become compost. You may remove this from the bottom of the pile and use it. Return the rest of the materials to the bin or pile location to continue decomposing.