QUESTION: Why is my compost pile not heating up? I have been composting for several months now, and nothing seems to be happening. Am I doing something wrong? – Jon W
ANSWER: There are a few different reasons a compost pile may fail to heat up. One possibility is that your compost may be too wet or too dry, or it may have too much of one particular material. It will take a lot more time for a large pile of just leaves, just sawdust, or any one ingredient to break down than it will if your compost has all kinds of ingredients and is well mixed.
However, you shouldn’t worry too much if your compost pile isn’t heating up. The concept of passive composting means your compost will continue decomposing regardless of how hot or cool the pile is. The only real difference is that a compost pile that isn’t hot will take longer to do its work.
There are a few things you can do to help get things going in a compost pile that isn’t heating up. Ingredients that contain a lot of carbon (also called “brown” materials) won’t make much of a difference, but ingredients that have lots of nitrogen (referred to as “green” materials) will help the microbes go to work, heating up your compost pile in the process. Use moderation when adding nitrogen-heavy ingredients, however, or your compost pile can get out of balance and begin to stink or develop a slimy texture.
Another thing you can do to help your compost pile heat up is to keep things damp—not dry, but not oversaturated, either. If the compost pile gets too wet, the microbes that heat things up won’t be able to get the oxygen they need, but if it’s too dry, the microbes can die of dehydration. If your pile gets too wet, you can spread it out to let it dry in the sun, then pile it up again once things are back to the right moisture level.