How do you make compost?

A good mixture of greens (nitrogen) and browns (carbon) is the key. Grass clippings and kitchen vegetable scraps (greens) need to be mixed with dried leaves and twigs (browns). The whole pile needs to be kept damp. I mix in about one part green, one part brown and one part soil; water well; and turn about every other week. In a couple of months, you have good rich compost.

In more detail:

Remember the A.D.A.M. principle for keeping the compost in balance.

1. A. Aliveness. Lots of micro-organisms, decomposers, so there is a mini ecosystem to break down the compost material. There should be plenty of visible life, such as worms, slaters and springtails. If not, adjust your Carbon:Nitrogen ratio to attract a diversity of critters.
2. D. Diversity. A variety of materials will attract a variety of life to break down the material (decomposers).
3. A. Air. More air = Less smell. Put twigs and sticks to allow air spaces in the pile, and turn once a week at least. Balanced: should smell like the earth. If it's smelly and acidic, turn more often; and add some garden lime, wood ash or dolomite. If it's too wet, add more dry material. If it decomposes without air (anaerobically), it produces methane, a dangerous greenhouse gas.
4. M. Moisture. Balanced compost should be moist, like a well wrung out sponge. To balance the mixture either add water, or add more dry material.

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You don't need a bin to make compost-a pile of leaves, grass clippings and other yard wastes will do-but a bin keeps the compost contained and looks neater. You can corral compost in a simple wire column made from a 4-foot wide by 8-foot long piece of stiff wire mesh.

You should have finished compost in about two months. You'll know your compost is finished when it no longer heats up and you can't identify any of the original materials. The compost should be dark brown, moist and earthy smelling. Dig finished compost into your garden's soil. You can use partially composted material as mulch.