Looking for a Warm Location this Winter?
Oh we've found it and you won't believe that it's right in your own backyard!
Yep! See, compost generates heat, thus making the material in your backyard composter or heap one of the warmer spots in your backyard all winter long. Even if your heap freezes don't fret, you can continue to add material. In fact, the freeze and thaw cycle will encourage the breakdown of the materials you add.
A frozen pile may compost slower, so why not try to relocate your composter to a sunny location or insulate your compost pile by covering the heap with a thick or dark plastic sheeting or a thick layer of leaves, hay or straw? If you decide to cover your pile, an "anaerobic" decomposition begins to occur (i.e. without oxygen). This will not prevent freezing (unless your heap is really big), but it will certainly delay it.
How the heap heats up…
So now we realize that the organic matter does not stop composting when it is cold. How much heat the pile generates will depend how on how close to the correct ratio of green and brown material along with the right amount of oxygen and moisture your pile contains. Also, a larger pile will be able to maintain a more stable temperature during the colder time of year than a smaller pile will. The "heat" in a compost pile is created by bacteria, which are working on organic matter even at a temperature below freezing. Psychrophilic bacteria (bacteria that work in the lowest temperature range) do their best work at about 13 degrees C (55 degrees F); but they are able to carry on right down to -18 degrees C (0 degrees F).
Psychrophiles give off a small amount of heat as a by-product of their work, and this heat causes a rise in ambient air temperature in the pile. As the temperature in a compost pile reaches the medium range, mesophilic bacteria become the active workers. These are the aerobic bacteria that do most of the decomposition work. Like us they thrive at 21-32 degrees C (70-90 degrees F) and just survive in the 4-21 C (40-70 F) and 32-43 C (90-110 F) range.
The heat generated as a by-product of the mesophiles` work raises the temperature in the pile even more, preparing the way for the real ``hot shots``: thermophiles. These bacteria work best in temperatures 40-93 C (104-200F). They work fast, and last only about three to five days. But what a three to five days! In that time, they turn green, gold, and tan organic material into a deep brown. If the pile is fed new organic matter or turned at a strategic time, the thermophilic action can occur again. (Turning brings fresh air to the microbes. Their numbers multiply quickly again and the pile reheats. However, the pile seldom heats as much as during the first build-up). Just remember, a frozen pile doesn't turn too easily…you just might have to wait until spring.
Information provided by the Fredericton Backyard Composters
