Composting
Passive Composting
If yard trimmings are left to accumulate in a pile for extended periods of time, it is no longer a mulch and it begins to enter the realm of composting. The simplest compost piles are increasingly larger mounds of organic trimmings that are left to sit and rot over time. For some people, these "passive-compost" piles are largely a backyard disposal system. Even the most passive composter, the truly lazy organics recycler, eventually finds themselves with “compost” and will put it to use growing plants. Once they do, they inevitably see the benefits of compost in soil texture, water holding capacity, and plant growth. Many of these passive-composting individuals gradually become active composters as they desire more compost.
But most people will never put more effort into their piles than is absolutely necessary. Getting a finished compost in three months instead of three years is apparently not worth the effort. Passive composters are by far in the majority. Studies have shown that most householders practice the "let it sit" sort of passive pile. Passive piles are the "layer in the bin" systems recommended by most composting books. The best thing about passive piles is that they work! I find it amazing that compost happens even if we do little to assist the process.
If you wish to start composting and are not looking to do a lot of work and wish to avoid the effort of mixing or turning an active compost pile, then just start! That's right, start composting today. There is little more to passive composting than making a pile somewhere in the yard. Purchase a bin, an enclosed plastic one if possible, and let your pile lie. That is all there is to passive composting. Rainfall, earthworms, and nature can be left to do their work, and given time, will decompose virtually any organic material fairly well. Passive composting piles can take many forms. Some are piles in the corner, most use a bin of some sort, and others use mounds of organic materials as a means of filling in low areas.
Once started, keep in mind that there is some wisdom in the practice of just letting sleeping piles lie. Moistened passive compost piles can be quite odorous if disturbed before their time. However, if the pile is never turned, there is little need to worry about odor. It is primarily the need for space, the desire to concentrate organic materials in a controlled area, and a need to process materials quickly in a nuisance-free manner that leads people to build active compost piles that require regular tending.
People should feel encouraged to be creative and to experiment within the bounds of neighborly cooperation. Some individuals have made satisfactory, although occasionally odorous, compost simply by letting grass clippings sit in sealed plastic bags for a season in the sun. One master gardener I know uses a three-pile system that he turns only once a year, producing rich humus in the third year. Most plastic bins have a door at the bottom where dark crumbly compost can be removed at the same rate that fresh table scraps and yard trimmings are placed on the top. Compost produced from passive piles is just as beneficial for the soil as is compost from active piles.
Mulching Versus Composting
Active composting has an advantage over mulching or passive piles because diseases and weed seeds are progressively destroyed when a compost pile is sustained at temperatures of at least 131°F for extended periods of time. Composting "cooks" weed seeds with high temperatures, whereas mulches help smother weeds. Active composting has the benefit of rapidly decomposing organic matter, where some mulching processes can take several years. However, thin layers of grass left on the lawn decompose at least as rapidly as they would in the compost pile.
Mulching is an excellent example of a "keep it simple" program. Soil organisms are perfectly capable of decomposing leaves and grass clippings without the high “thermophilic” temperatures of compost piles. After all, nature doesn't gather thin layers of organic material into a concentrated pile, water the layers, turn and aerate the heap, and later spread the finished compost back into thin layers. Thin layers are often best left as thin layers. The roots of plants care little whether the organic matter in the soil was produced from the best hot compost piles or from years of accumulated thin layers. Organic matter is organic matter, and the soil benefits regardless of the technique of decomposition.
