With the threat of invasive jumping worms now visibly “surfacing” in McLean County, it’s more important than ever to ensure your compost is reaching a proper temperature of 131 degrees F. We sometimes say that compost is “cooking”, but a slow-cooker version of this process is not enough to ensure safety. So let’s light it up, and think in terms of fanning the flames.
In order to burn hot, a fire needs fuel, oxygen, and controlled moisture levels.
The fuel in your compost pile is nitrogen, supplied by the materials we call greens. Greens include carrot tops, apple cores, and banana peels, as well as live plant material recently trimmed or pulled from your yard. Any fresh fruit or vegetable scraps are considered greens. As vegetable matter ages, the nitrogen quickly escapes. Older plant material such as dry leaves and grass are called browns. They supply carbon, but not much nitrogen. For basic composting, we aim for a baseline ratio of about half greens and half browns.
Even where fuel is abundant, one way to smother a flame is to deprive it of oxygen. The same is true for cooking your compost. Without plenty of oxygen, the biological activity and chemical reactions that turn garbage into gardener’s gold slow down, and the pile cools off. That’s why we emphasize building the pile in a way that creates air space. As items break down and settle to fill those spaces, stirring is essential to re-introduce oxygen.
It’s no mystery what would happen if you open a fire hydrant onto your backyard grill, or if a downpour fills your fire pit with water. Your compost pile also needs to be protected from too much water. Yet the living organisms that do the work of composting consume and excrete some water. A little moisture is needed to keep those organisms alive, and the “compost tea“ that results needs to drain from the pile. Drought, rain, and build-up can cause parts of your pile to have too little or too much moisture. Proper cover, drainage, and stirring can help keep moisture distributed correctly throughout your bin.
If your compost is not reaching appropriate temperatures, determine which of these factors might be contributing.
Fuel – inadequate nitrogen
- You may have burned up the fuel in the center of your pile, while plenty of nitrogen remains available around the edges. Stir to re-incorporate those greens for more even distribution.
- Increase the ratio of greens to browns. Up to 60/40
- Add higher nitrogen greens (list examples)
Commercial products do exist, that are designed to provide a nitrogen boost for backyard compost piles. While such a product might kick start the process, please be aware that such products may have detrimental impact on the environment by contributing to air, water and soil pollution. We do not recommend use of these products.
- Turn, turn, turn! The hotter your pile, the faster it will decompose to use existing oxygen and fill air spaces. If that’s happening, you’re doing great! Stir as often as needed to fluff the pile and introduce more oxygen
- Increase the permeability of your container, by adding or enlarging holes in the sides
- Excess moisture may fill the spaces needed for oxygen – see below for tips on moisture management
Moisture deficiency: If the pile is drier than a wrung-out sponge or there is an excess of ants and other insect visitors
- Sprinkle lightly with water, then stir to incorporate
- Add more greens ensuring they are covered by browns
Moisture excess: If the pile is wetter than a wrung-out sponge
- Ensure adequate drainage so that “compost tea“ can move away from the pile
- Cover as needed to keep rain out, for example with a lid or a tarp
- Stir to create additional aeration and opportunity for evaporation
- Add more browns to the mixture
Unwanted Animal Visitors: If your pile is getting some animal visitors like raccoons, cats, or mice
- Ensure that meat, dairy, fish, or bones have been added to your pile. If so, remove these items
- Cover with browns
If none of the above work, please call us at 309-4554-3169 for further assistance in troubleshooting your compost pile. If you are unable to make an adjustment that is necessary to compost properly, you may also wish to consider signing up for our Community Compost program.