A. You are right in being concerned that your compost bin isn't heating up. In order for your compost to be relatively free of pests, weed seeds and insect eggs, the internal temperature should reach at least 160 degrees F. However, before we answer your burning question, let's make sure we've got the composting basics down.
Ideally, your compost bin should be approximately three to five feet in diameter with enough openings in the sides to allow for good air circulation. Now, besides the organic material you'll be placing into your bin, successful composting depends on air, water and nitrogen. These will provide the proper conditions for the microorganisms, like bacteria and fungi, to break down the organic material. It is this breaking down process that generates the heat.
Layering is the easiest way to begin. The organic material should be a good mix of "browns" and "greens" to provide the best balance for the microorganisms to do their work. Greens like grass clippings, green leaves or cow manure, are the source for the essential nitrogen. Browns can include straw or any other type of dry and dead plants. Broken branches placed as the first layer will help to provide needed air pockets at the base. Next begin layering - for each six to eight inches of organic material add one inch of compost or garden soil. This is your source for the microorganisms. Add a one inch layer of cow manure or a cup of nitrogen fertilizer and repeat the layers, being sure to moisten each layer.
Now that we've created the structure, it's time for troubleshooting. As mentioned earlier, heat is generated when the organic materials are broken down by the microorganisms. The process of making compost is quite simple, but conditions must be favorable for these microorganisms. Air is the most essential ingredient; in fact, the process of composting is dependent upon on it. Be sure to turn the layers weekly during the summer and monthly during the winter. With nitrogen, too much can kill the microorganisms, while not enough will "starve" them. It may be necessary to add some fresh grass clippings or manure. As a rule of thumb, the bin should be as moist as a damp sponge. Too much moisture does not allow for sufficient air circulation. The process of making compost will take approximately 90 to 120 days; enough time to start a few more bins if you have the room. That way you'll have a steady source of compost to use as an excellent soil amendment or mulch. Finally, think of compost as a living organism, and like all living things, it needs air, food and water to thrive!