Theories of composting

There are several different ways of making compost.

The one we always hear about and read in the gardening magazines is the hot method. This method involves adding the right kinds of plant materials in proper amounts to provide the proper nitrogen to carbon ratio. That ratio speeds up the decomposition rate which in turn raises the temperature of the compost heap.

A hot compost pile needs to be turned every other day or so to help oxygen reach the microbes that are doing all the work breaking down the material in the pile. The temperature in a hot compost will easily get over 140 degrees F killing weed seeds and disease causing fungus.

If the temperature rises much over 140 degrees F, the good bacteria in the pile will be killed too. Plus, spontaneous combustion can occur causing a potentially hazardous fire. Turning every other day cools down the pile. Serious composters use temperature probes to monitor their compost to make sure it is cooking at the proper rate.

The nonscientific way of composting is to just throw everything compostable onto a big pile and walk away. Don’t expend the time and energy turning the stuff; don’t measure the temperature; don’t add water. This is called cold composting — and compost will form under those conditions.

The main disadvantage is that it won’t kill disease organisms or weed seeds. Also, it takes much longer to make finished compost.

I found earthworms this week thriving in my cold compost pile. Had this been a hot pile, the heat would have killed any worms that happened to be in there.

Curiously, cold compost has more plant nutrients in it than hot compost. All of that heat generation releases nitrogen into the air. Also, cold compost seems to have the ability to suppress diseases better than hot compost — just don’t make the mistake of adding diseased plants to a cold compost pile.

I use the cold composting method partly because of time constraints. I have a feeling most gardeners do the same thing for the same reason. What’s your composting philosophy?