What Does It Take to Make Compost?

The good news is that anybody can make compost. Actually, compost will make itself without anybody. Consider a maple tree near a fence line. Each year it sheds its leaves, and some of those leaves are blown against the fence where they pile up. In time, the bottom layer of those leaves is no longer recognizable as leaves, but transformed into a dark, sweet-smelling, crumbly soil.
All organic matter rots. You can speed up the process by combining different types of matter, ventilating the mix to add oxygen, and keeping it moist. When you control the circumstances, the process speeds up considerably. You can make compost in weeks, not years.

In terms of composting, gardeners consider organic matter primarily a carbon-based material or a nitrogen-based material. Microbes burn approximately one part of nitrogen for every twenty-five parts of carbon they digest. So you need at least one part of nitrogen material for every twenty-five parts of carbon material. More nitrogen material is fine if you have it. Materials high in nitrogen, such as alfalfa meal, blood meal, or urea, act as pile activators by jump-starting the microbes into action. Which materials are nitrogen and which are carbon? In general the easiest way to tell is that materials higher in nitrogen are green and those higher in carbon are brown. Other ingredients add phosphorus, potassium, and trace minerals. Egg shells, wood ashes, banana skins, melon rinds, orange peels, stale bread, apple peels, potato skins, pea pods, and tea leaves are great for composting.

There are a few things that, although they are organic matter, do not belong in a garden compost pile. Leave the following out of the compost pile:

• Weeds that have gone to seed. The seeds may survive.
• Obviously diseased or insect-infested material.
• Any meat, grease, or fat. It stinks and attracts vermin.
• Cat and dog feces, which may transfer parasites to the garden.
• Grass clippings or weeds that have been treated with weed killers. Chemicals may persist and poison the garden.
• Pine needles or large branches. They don't harm the pile but take years to decompose.