Composting is nature’s way of recycling organic material back into the soil.

The idea is to take what would normally go in your trash can – green waste and food scraps – and transform it into a rich, fertile soil amendment for your potted plants and yard.

Aside from reducing the waste stream reaching island landfills, home composting can be "green" in another way by providing cost savings to consumers.

A bag of Menehune Magic, a potting soil made from the county’s recycled green waste, costs $3.85 to $5.85 at retail outlets. Lawn and garden blends cost $37 per cubic yard (one cubic yard fills a small pickup truck bed), while a higher-end greens blend costs $70 per cubic yard.

There are many ways to compost at home, but two basic methods are a backyard pile and worm composting, also known as vermicomposting.

A backyard setup is ideal for tree trimmings, grass clippings and other yard waste as well as select food waste. Worm composting is an option for those who don’t have a yard.

"If you have the time and the inclination, 75 percent of your household trash can be

composted," said Jeremai Cann, who teaches both methods at the Green House, a nonprofit group in Pauoa.

A yard compost pile comprises four ingredients: browns (dead leaves, branches, twigs), greens (grass clippings, vegetable scraps, coffee grounds), air and water.

The brown materials are rich in carbon, while the greens are high in nitrogen. These two, combined with air and water, will help microscopic animal organisms transform them into compost.

While some people prefer to keep their compost pile contained in a wood bin, chicken-wire enclosure or other homemade or store-bought system, you can start with an open pile in a level area in your back yard.

Ideally, the compost pile should be in a dry, shady or partly shady spot near a water source – preferably out of sight.

To build an enclosure, Jeremy Martinez of Olomana Gardens in Waimanalo advises using lumber, re-purposed shipping crates or chicken wire.

The hurdle most homeowners have is lack of space in their yard, but Martinez says even a small yard can accommodate a compost pile. The minimum dimensions are just 3 feet wide by 3 feet tall and 3 feet deep.

The most common mistake beginners make is building a pile that is too small, he says.

For faster decomposition, you can chop your browns and greens to help them break down more quickly. Martinez also recommends turning the pile on a regular basis with a pitchfork to produce ready-to-use compost more quickly – sometimes in just 14 days.

Cann’s approach to backyard composting is even simpler, without an enclosure.

In his "Garbage to Gold" workshop, Cann teaches students to start with a base of dried banana leaves and palm fronds, covered by a second layer of greens from the garden and topped by another layer of browns.

The top layer should be level, covered with burlap sacks to keep pests away.

You can add to the pile by making a hole in the middle, tossing in food scraps, then re-covering.

Cann says turning his compost "bed" is not necessary, as he prefers letting nature do the work.

The ratio of carbon to nitrogen in a compost heap should be 25-to-1, according to Martinez. That means about 24 shovelfuls of dead leaves to one shovelful of food waste. Too much green waste and the pile tends to smell.

Maintaining your compost pile is an art, but if done right it should be a well-balanced system that gives off no odors.

If your compost heap starts to stink, it might not be getting enough aeration. Try to turn and loosen the pile. If the odor smells like ammonia, you might have too much nitrogen (green material) and should add more carbon (brown material).

If the pile is too wet, add more carbon and protect it from the rain. If too dry, then add water.

To avoid attracting flies or animals, make sure you are not adding inappropriate material such as dairy products, fats, grease or meat. You might also want to consider getting a rodent-proof cover for your bin.

Diseased plants, pesticide-treated yard waste, plastic, rubber and pet waste also do not belong in a compost pile.

Martinez advises checking first with your homeowners association, if you have one, because many master-planned communities will allow composting only if done in a container.