We’ve all heard the term ‘black gold’ and know that generally it in reference to oil. But I believe there is another way of using that term and that is in reference to compost. Nature has given us the example of using fallen leaves to return all the minerals and other nutrients back to the soil from where they originated. Composting is the process whereby organic materials decompose by the actions of microbes in the soil, with the presence of oxygen and water. The organic matter turns black in the process, thus my use of the term black gold for compost. When man first began to plant seeds and harvest the results to put on his table, it was quite natural for him to observe what nature was doing with the unwanted portion of the crop as well as the leaves that fell from the surrounding trees. Unfortunately, because land was cheap and readily available, our ancestors burned off most of the waste products of his crops and table. As civilization grew, the importance of returning the nutrients taken from the soil became more apparent to those who studied the growing process and the soil itself. From an ecological viewpoint it just makes good sense to do what nature does and recycle by composting.
As our society grew, we gradually became a throwaway society. What we felt was of no more use or worth to us we threw away, eventually into garbage dumps or landfills. As these landfills filled and became more expensive to expand, laws were passed to limit the dumping of leaves and grass clippings into the landfills. The University of Minnesota Extension Service published fact sheets about composting, how to compost and what should and should not be put into compost piles. These same publications discuss the benefits of composting and many cities passed specific laws in order to control unsightly compost piles. In addition, counties set up composting sites where homeowners could take their leaves, grass clippings, and other yard wastes. The finished product could be taken and incorporated into the homeowner’s garden soils.
Specific recommendations from the University addressed what can be composted in home compost piles. Besides grass and leaves many other organic materials may be used but there are some specific exceptions. Compostable materials include faded flowers, non-diseased plant parts, shrub trimmings and twigs less than 1/4 inch in diameter, weeds without seed heads, leaves, grass clippings mixed with other organic materials, hay and straw, and small amounts of sawdust and wood ashes. All of these are what we commonly call yard waste. But we should not forget other waste products that originate indoors. These include fruit and vegetable skins and other waste parts except the seeds, tea leaves, coffee grounds, and eggshells. Materials that should not be added to the compost pile are disease or insect infested plant parts, pet feces, meat products, including bones, whole eggs, greasy/oily materials, and dairy products. These items will attract rodents and other animals.
In order to compost these materials properly, and to conform to local laws, the compost pile should be a confined pile rather than open or loose. This also saves space and makes for a neater appearance. It will also speed up the composting process. We made 5’ x 5’ panels using treated 2x4s with 2” x 4” wire fencing stapled to the wood frame giving us a 5-foot square bin by 5-feet high. Rather than assembling them permanently by nailing the panels together, we used two pairs of large screw hooks and eyes at each corner, approximately one foot from the top and the bottom. This made the bins portable and easily accessed in order to turn the composting materials. This is the typical size recommended for backyard composting. You can also make an even simpler bin using wire fencing and metal posts. We made seven panels hooked together to make two bins, allowing us to turn the material from one to the other. The minimum structure should be 4-foot square by 4-feet high. Smaller composting bins are sold commercially, but they are not as efficient.
The pile should be located preferably in partial sun, where it will not be offensive to your neighbors, or where it will not interfere with normal activities in you yard. In some localities the regulations require that the compost bin(s) should be no closer that 5 feet from the lot line.
The compost materials should be added to the bin in layers of about 8 to 10 inches. Grass clippings, if used, should be mixed with other materials. Grass in layers greater than 3 or 4 inches will decompose slowly and anaerobically, that is, without oxygen, causing undesirable odors. Over each layer add approximately 1/2 cup of an inexpensive high-nitrogen fertilizer and several shovels of garden soil or finished compost. Add water so the layer is moist but not soggy. Continue building the pile is successive layers. Efficient decomposition requires the presence of soil microbes, water and oxygen. The pile should be turned and mixed occasionally to prevent odors and speed up the composting process. We tried to do this about every 10 days during the warm weather. We added our indoor waste products by burying them in the pile or when turning the pile. You can purchase a long metal probe thermometer to use to help knowing when to turn the pile. The temperature in the center of an actively working pile should be between 130 and 160 degrees F.
A well-maintained pile should provide a finished product in 2 to 4 months. This material will have a rich earthy odor. It will have no signs of leaf or plant part structure to it. It can be used in the gardens or in potting soil mixes. Yearly additions can be made to the gardens by adding a 1 to 2 inch layer in the fall to either sandy or clayey soils and incorporating it into the to 6 to 8 inches. You can also use it as mulch around plants in your annual or perennial garden by putting a 3 to 4 inch layer of compost around the base of the plants. For potting soils, add no more than about 1/4 by volume to your potting mix prior to filling your pots or containers. -- Happy composting!
Leonard Gloeb
