The Composting Process

There are six key elements to a composting process that you need to be aware of:

1) Nutrient balance - especially the ratio of carbon to nitrogen (C:N). This is controlled mostly by the types of materials you add to your mixture. Microorganisms use carbon materials (like carbohydrates) for their energy and they use nitrogen to build up their proteins. The ideal C:N ratio is 30:1. Too much nitrogen and the pile will give off an odor; too much carbon in the pile will not sufficiently heat up and the composting process will take longer.

2) Moisture content - Your compost pile should remain moist but not wet. It should feel damp but if you can squeeze water out of it is too wet. Microorganisms need moisture and oxygen to survive. As your pile heats up, especially in the summer, moisture evaporates quickly. If the pile dries out, the bacteria will die.

3) Air - Your little microorganisms will do their best work with adequate air space. The compost pile should be freestanding, or, if in a bin, should be encased with chicken wire or some means of ventilation. Too much of one kind of material like grass clippings can compact the pile. Mixing in course material like wood chips or straw will provide greater space. You must periodically turn your pile with a spading fork to increase aeration. How often you do this is determined by the temperature of the pile.

4) Temperature - Your compost pile will produce heat. As the bacteria is breaking down the vegetation in the pile it is giving off a lot of heat. The best temperature range for your pile is between 110° and 140°. If the pile gets too hot it can kill the bacteria. Turning your pile will help to regulate the temperature and replenish oxygen levels. The best time to turn your pile is when the temperature begins to drop in the pile. This means the oxygen has been used up.

5) Pile Size - The ideal size for an effective compost pile is 4 feet high by 4 feet deep by however long you like it to be. The pile needs to be large enough to insulate itself against heat loss. Piles are too big tend to compact and lose oxygen.

6) Curing - When your compost pile stops heating up when you turn it, is still not quite ready to be added to your garden. Some of the low-activity bacteria is now working to further break down the large chunks and finishing off the mixture with sustainable nutrients and re-colonizing beneficial bacteria. Maintain moisture in your pile and turn it occasionally.