There are three essential components for creating great compost... food, air, and water. Providing air and water is relatively easy. You just need to be sure that you have the right amounts. Providing the right food – which most people call the ingredients of their compost – requires just a little more effort.

The three main sources of composting ingredients are:

Lawns and gardens provide the majority of composting ingredients, namely grass clippings, leaves, and plants.

Kitchens and Dining Rooms usually provide a much smaller volume, but a great variety of ingredients, like coffee grounds, vegetable peels, and egg shells from the kitchen, and leftovers from the dining room.

Farmers are often great sources for manure, and friends are often happy to share leaves and grass clippings (especially if they don't have their own composting bin).

Composting ingredients are generally classified as "greens" or "browns." Green materials are high in nitrogen; brown materials are higher in carbon. Your composting bins need to have both greens and browns to produce compost.

Just as the best diet for our health is a "balanced" diet, the best ingredients for composting bins consist of a balance of "brown" and "green" composting materials.

The ideal balance of browns and greens a 4-to-1 ratio, by weight. That is, for every four pounds of browns, you should have one pound of greens.

Having too much brown material is rarely a problem... it'll just slow down the composting pace. Too many "greens" is usually the problem associated with composting. A big bin of kitchen scraps (without any brown materials) will never become compost... it will simply be a pile of smelly garbage. Similarly, a bin that consists of grass clippings alone will be a matted, soggy, smelly mess.

In most parts of the country, dry leaves are readily available (some people might say a nuisance) in the fall. For really great compost, collect as many dry leaves as you can store. If possible, shred them with a lawn mower or shredding vacuum tool... you'll need fewer bags to store them, and they're the number 1 ingredient for great compost. It's what makes the typical forest floor so fertile, soft, and sweet-smelling.

Removing leaves from your lawn is also good for your grass. Notice that the typical mature forest doesn't have any grass growing around the trees; the leaves choke out virtually all grass and small plants.

If you have a lot of shredded dry leaves, you should have no trouble balancing your compost bins with a variety of green materials, such as kitchen scraps and grass clippings. Animal manure is also a great source of green (high nitrogen) food for your compost; but, of course, you'll probably want to use manures sparingly, if at all, unless you live on a farm or have a huge quantity of brown ingredients to compost.

You can add almost any organic material to your compost, and in small quantities you're unlikely to upset the balance of "greens" and "browns." To see an interesting list of the many items that can be added to your compost, click here.

The best way to keep your compost bin working efficiently is to turn it, so that you mix the green and brown materials, and distribute water and air throughout the mixture. For more information on the importance of turning, see Turning Your Composting Bins.