Cleaning the garden at this time of year reaps untold treasures since the fading garden provides abundant material for composting. Leaves, grass clippings and perennials past their prime are plentiful. Shortly, the annuals, bitten by frost, will be as unsightly in these dying days of autumn as they were lovely during the summer. And, they too will be plucked out and carted off.

It would be a shame to let all this wonderful garden stuff go to waste rather than to let it go to work. Mixed with other organic matter, such as kitchen scraps and soil with its resident fungi and microscopic critters, the ingredients combine to begin the wondrous process of producing compost.

How does the composting process work?

The chemistry of composting is simple the fungi break down the cellulose and complex molecules of the organic matter as the temperature of the pile rises up to 160 degrees. After a while, the bacteria take over the process and complete the decomposition.

The compost pile needs oxygen and moisture so the microbes can work their best. Turning the pile over with a pitchfork every now and then allows oxygen into the pile. Rainwater supplies the moisture. Too much water slows down the decaying process, though.

Any precautions?

Yes. Do not add pet or human waste matter to the compost pile. These can be a health hazard by transmitting diseases. Also, avoid adding meat, bones, grease, whole eggs and dairy products to the pile. Rodents are attracted to these things. Also, do not add garden material that has been chemically treated.

Do I need an elaborate bin?

Composting happens. So, make it easy on yourself, too. Some people merely pile up the organic matter in an out-of-the-way place; others stuff everything in a 30-40 gallon black plastic bag, add a spoonful of high nitrogen fertilizer, a bit of water and wait and wait. (This process can take up to one year before the compost is ready to use in the garden.) Commercially manufactured bins are also available. All may not work as advertised.

You can build a simple structure using wooden slats, wire, bricks or cement blocks in which to “heap” your ingredients. Do not use chemically treated wood in the construction of the compost bin, lest the chemicals leach into the compost. Woods naturally resistant to rot, such as cypress or redwood, are ideal.

What size should I make my compost bin?

The compost bin should be big enough to hold a sufficient volume of organic material to allow decomposition. A circular structure should be nine feet in diameter. A rectangular one should be five feet wide and 10 feet long. A popular composting structure is the two- or three-bin one. Each bin should be three to five feet in dimension.

Where should I locate the compost bin?

Place the compost pile in a partially sunny location close to where you will use it. If it is exposed to too much sun or wind, the pile will dry out and need moisture added to it. Even though compost bins are an excellent way to recycle garden matter and demonstrate environmentally sound gardening practices, be a good neighbor and locate it out of sight or camouflage it well. Avoid placing it too near trees. Tree roots will grow into the bottom of the pile, making handling of the finished compost difficult.

How do I know the compost pile is “working?”

Within two to three weeks, the pile should shrink. If it has not, provide aeration or moisture.

Within four to five weeks the temperature at the center of the pile should be hot, indicating that the fungi are working to decompose the organic material. To check this, plunge a long probe into the pile and pull it out. If it feels warm to the touch when removed, the decaying process is occurring.

Within three to four months, the pile will have an earthy smell and be about half its original size. Its texture will dark and crumbly.

Six months after aging, the compost should be ready to use.

Expect a slower process during the winter months. Nonetheless, get ahead of the game by creating a place to collect the abundance of organic matter “falling” at this time of year.

Carol Boncella is education coordinator at Lawrence Memorial Hospital and home and garden writer for the Journal-World.