Hot or cold?
At the ends of the composting spectrum are two methods: hot and cold. A cold composting system is one in which organic waste is simply dumped in a pile to decompose. The gardener expends little or no energy managing the pile and just waits for it to decompose. Hot composting requires a system that raises temperatures high enough and for a long enough time to destroy weed seeds and plant pathogens. This requires some work on the part of the gardener, either up front with careful layering of materials, or later on with maintenance of pile temperatures. In between the two techniques are numerous degrees of intervention.
Actually, the term cold composting is a misnomer, as even in an untended pile, temperatures will rise. I use these terms to differentiate between active and passive composting. A cold pile may be as sophisticated as a three-bin system or as simple as a heap of leaves. The beauty of cold composting is that you just pick a spot to plop your organic refuse and then add to it. Although this non-method appeals to the laziness in all of us, cold composting takes longer to produce finished compost.
The hot method requires monitoring the moisture content of the pile, aerating to keep oxygen-hungry microbes fueled, and balancing the brown and green material you add to your system. Planning, vigilance, and work bring about fast decomposition of organic material, with bin temperatures high enough to destroy most plant pathogens and weed seeds.
Composting is a method of recycling naturally decomposing matter. Ingredients, size of the pile, local weather conditions, and your maintenance habits will affect the outcome. Note that shredded leaves, chipped wood, and chopped food scraps generally decompose more quickly than whole or large pieces.
HOT, OR ACTIVE COMPOSTING
The quickest way to produce rich garden humus is to create a hot, or active, compost pile. It is called “hot” because it can reach an internal temperature of 160°F (140°F is best) and “active” because it destroys, essentially by cooking, weed seeds and disease-causing organisms. The size of the pile, the ingredients, and their arrangements in layers are key to reaching that desired outcome.
Size: A hot compost pile should be a 3-foot cube, at minimum; a 4-foot cube is preferred. The pile will shrink as the ingredients decompose.
Ingredients:
One part high-carbon materials (shredded, dry plant matter such as leaves, twigs, woody stems, corn cobs)
One part high-nitrogen green plant matter (green plant and vegetable refuse, grass clippings, weeds, trimmings, kitchen scraps—but avoid meat, dairy, and fat) and good-quality soil
Pile the ingredients like a layer cake, with 2 to 4 carbon materials on the bottom (twigs and woody stems here will help air to circulate into the pile). Next, add a layer of soil. Add 2 to 4 inches of nitrogen-based materials, followed by soil. Repeat until the pile reaches 2 to 3 feet high.
Soak the pile at its start and water periodically; its consistency should be that of a damp sponge.
Add air to the interior of the pile by punching holes in its sides or by pushing 1- to 2-foot lengths of pipe into it.
Check the temperature of the pile with a compost thermometer or an old kitchen thermometer. A temperature of 110°F to 140°F is desirable. If you have no heat or insufficient heat, add nitrogen in the form of soft green ingredients or organic fertilizer.
If a foul odor emanates from the pile, flip the compost to introduce more air. And consider: Did you add meat or dairy products? Remove and discard them, if possible.
Once a week, or as soon as the center starts to cool down, turn the pile. Move materials from the center of the pile to the outside. (For usable compost in 1 to 3 months, turn it every other week; for finished compost within a month, turn it every couple of days.)
COLD, OR PASSIVE COMPOSTING
Cold, or passive, composting uses many of the same type of ingredients as hot composting and requires less effort from the gardener, yet the decomposition takes substantially longer—a year or more.
To cold compost, pile organic materials (leaves, grass clippings, soil, manures—but avoid dog, cat, and human waste) as you find or accumulate them. Bury kitchen scraps in the center of the pile to deter insects and animals. Avoid adding meat, dairy, and fat. Also avoid weeds; cold compost piles do not reach high temperatures and do not kill weed seeds. (In fact, weeds may germinate in a cold pile.)
COMPOSTABLE GOODS
In addition to the ingredients mentioned above, any of these items may be added to a compost pile:
Coffee grounds and loose tea or compostable tea bags (note that most tea bags are not fully compostable so tear them before adding to compost)
Dry goods (crackers, flour, spices)
Eggshells
Hair
Nutshells
Pasta (cooked or uncooked)
Seaweed
Shredded paper/newspaper
http://blog.oregonlive.com/kympokorny/2010/11/cold_compost_not_a_bad_alterna.html
http://www.growinganything.com/compost-how-to-make.html
http://www.rodalesorganiclife.com/garden/7-solutions-common-compost-problems