Compost Bin Isn’t Making Much Compost

Q: I have an insulated, 7.5 cubic foot compost bin but I haven’t had much compost. I turn the compost once a week. Is that too much?

A: I think there could be three problems going on at the same time: temperature, moisture, and oxygen. Microbes that chew up your kitchen scraps always need a bit of warmth to do their work. Even though your composter is insulated, in fall and winter the heat naturally coming from the microbes can be quickly lost. Get a compost thermometer and check the temperature in the center of the pile. It should be at least 100 degrees. If it’s not, mix up a gallon of houseplant fertilizer and get a helper to slowly pour it into the composter as you turn the contents.

You’re trying to get the fertilizer into contact with every clump of compost. Put the lid back on and wait a week, with no turning. Things should be heating up by then. If it’s warm but not hot, close and wait another week. If it’s still not hot check the moisture level. Ideally, moisture content throughout the pile should be comparable to a wrung-out sponge.

You can fix a soggy pile by more turning. Eventually, you’ll get a feel for how often to turn the compost to keep the pile hot in the center. Turning at these intervals should introduce enough oxygen to keep the microbes happy and produce compost for you.