Pile it on. Composting turns waste into rich garden soil. DENIZENS OF THE HEAP

A FEW years ago while I was unloading a defunct kitchen stove at the town dump, a man backed up a station wagon against the garbage hopper. In a trice he dumped his load and was gone. The first fall frost had arrived a few nights before. With an efficiency that was admirable, he had cleaned up his garden and disposed of the spent plants at the town dump. But what a waste!

Those plants, when put in a compost pile, could have been used to promote the next generation of flowers, or fatten the carrots and flavor the tomatoes in next year's garden.

Standard composting is the gathering together of volumes of dead and dying plants so that they turn back into a rich, dark soil in one specified corner of the garden. Basically composting simply involves making a heap of all yard waste, leaves, and even organic kitchen waste.

Why is compost worth the effort?

Because it adds to the soil what chemical fertilizers cannot: humus, enzymes, microflora. You can simply pile the waste in a mound, roughly 4 to 5 feet in diameter (or square) and 4 or more feet high, and leave it.

Or you can make a series of enclosures out of concrete, wire, or wood that will hold your heap in a tidy vertical shape. One of the simplest is to take a roll of chicken wire, 4 feet high and 12 to 15 feet long, and form it into a circular cage (3 to 4 feet in diameter).

Eventually a host of fungi and bacteria, followed by earthworms and other denizens of the heap, will decompose it into a rich black soil without any further attention from you. You can speed up the process by:

1.Moistening the pile in dry weather so that the contents glisten without being so wet that you can wring out any water.

2.Mixing green and dry materials together. Most year-end garden waste is a nice mix of green and brown residue. Dry autumn leaves need the addition of green material (lawn cuttings) and/or kitchen waste to get a good balance.

3.Cutting or shredding the material before placing it on the pile. Physically breaking up the material allows the decomposing bacteria to enter and start their work more quickly.

4.Turning the pile. When the weather is warm and the material has been shredded, turning over the pile every day will give you pretty usable compost within two to three weeks. A timesaving device is a compost aerator, a stick-shaped probe that pushes easily into the pile. When it is withdrawn, two hinged flaps open out to loosen the material, letting in fresh oxygen.

5.Inoculating the pile. Specially formulated cultures can help the decomposing process, especially if yours is a new garden where soils might be low in humus and microbial life. These cultures are available from garden centers and several mail-order sources. Be sure to check that they are a living culture and not merely a chemical stimulant.

6.Insulating the pile. In the colder north, composting slows to a crawl and all but stops during the height of winter. But insulating the heap will keep it operating for a lot longer. Last fall I gathered in bags of leaves from neighborhood streets and piled them around and on top of my wire-enclosed compost pile. If you try this approach, remember to remove the bags as soon as the warm winds of spring start blowing.

By planting time next year, your compost should be ready to use, even if it is not all broken down. Shredding it at this time produces a beautifully smooth material. Otherwise, you can always sieve the compost if it is too coarse for your liking. Use the screened material in the planting holes and spread the rest over the bed as a mulch.