Most yard wastes can be composted, including leaves, grass clippings, plant stalks, vines, weeds, twigs and branches. Compostable food wastes include fruit and vegetable scraps, coffee grounds, eggshells and nutshells. Other compostable materials are hair clippings, feathers, straw, livestock manure, bonemeal and bloodmeal.
Materials should NOT be composted if they promote disease, cause odors, attract pests, or create other nuisances. These include meat, fish, poultry, dairy products, foods containing animal fats, human/pet feces, weeds with developed seed heads, and plants infected with or highly susceptible to disease, such as roses and peonies.
Materials that should be composted only in limited amounts include wood ashes (a source of lime), sawdust (requires extra nitrogen), plants treated with herbicides or pesticides (the chemicals need time for thorough decomposition), and black and white newsprint (composts slowly, so it should comprise no more than 10% by weight of the total pile).
1. SHREDDED ORGANIC WASTES. Shredding, chopping or even bruising organic materials hastens decay. One way to shred leaves is to mow the lawn before raking, collecting the shredded leaves in the mower bag. It takes at least 34 cubic feet of shredded material to form a compost pile.
2. GOOD LOCATION. The compost pile should be located in a warm area and protected from overexposure to wind and too much direct sunlight. While heat and air facilitate composting, overexposure dries the materials. The location should not offend neighbors.
3. NITROGEN. Nitrogen accelerates composting. Good sources include fresh grass clippings, manure, bloodmeal and nitrogenous fertilizer. Lime should be used sparingly if at all. It enhances decomposition, but too much causes nitrogen loss, and it usually isn`t necessary unless the pile contains large amounts of pine and spruce needles or fruit wastes.
4. AIR. The compost pile and its enclosure should be well ventilated. Some decay will occur without oxygen, but the process is slow and causes odors.
5.WATER. Materials in the compost pile should be kept as moist as a squeezed sponge. Too little or too much water retards decomposition. Overwatering causes odors and loss of nutrients.
BUILDING AN ENCLOSURE
Enclosing the compost pile saves space and prevents litter. The enclosure should be collapsible or provide an entry large enough to permit the pile to be turned. It should measure at least 4'X4'X4' (a pile under 3 cubic feet generally does not decompose properly), but no taller than 6' (too much weight causes compaction and loss of oxygen). The enclosure can be built of wood, pallets, hay bales, cinder blocks, stakes and chicken wire, or snow fencing. Prefabricated compost bins are also available.
BUILDING THE PILE
Aside from the basic requirements for decomposition and preventing odors and other nuisances, there is no set method for building a compost pile. One technique may be faster than another, but a variety of methods work well. Piles can be built in layers to ensure the proper proportion of carbon (e.g., leaves, woody materials) to nitrogen (grass, fertilizer), but the layers should be thoroughly intermixed after the pile is built.
Turning and mixing the pile with a pitchfork or shovel, or shifting it into another bin, provides the oxygen necessary for decomposition and compensates for excess moisture. A pile that is not mixed may take 34 times longer to decompose. Recommendations for mixing the pile vary from every 3 days to every 6 weeks. More frequent turning results in faster composting. Odors indicate that the pile is too damp or lacks oxygen, and that more frequent turning is necessary.
Occasional watering may be necessary to keep the pile damp, especially in dry weather. Covering the pile with black plastic reduces the need for watering; it also prevents rainwater from leaching out the nutrients.
A pile that is decomposing properly should generate temperatures of 140°-160°F at its center. The heat kills most weed seeds, insect eggs and diseases. The pile should be turned when the center begins to cool. Turning the pile maintains the temperature and ensures that all material is exposed to the center heat. When the compost is finished, the pile will no longer heat up.
Small amounts of fresh materials may be added but should be buried inside the pile to avoid pests and speed composting. It is better to add fresh materials to a new pile.
Finished compost is dark brown, crumbly, and has an earthy odor. Depending upon seasonal temperatures, a well-built, well-tended pile generally yields finished compost in 2 weeks to 4 months. An unattended pile made with unshredded material may take longer than a year to decompose.
ALTERNATE COMPOSTING METHODS: Using compost tumblers
Under normal environmental conditions, both the open (hot) pile control and the tumblers yielded rich, finished compost in about 10 weeks. The tumblers were certainly easier to use than turning an open pile with a pitchfork, but they did not appreciably increase the speed of production when compared to a properly managed open pile. Ease of turning is probably the main benefit tumblers offer, some are easier to turn than others.
Compost tumblers do have advantages in addition to ease of turning. By and large, they are clean, neat, unobtrusive, pest-resistant and odor-free. Because of this, tumblers often can be used in urban and suburban areas, where local laws or restrictive covenants may prohibit open compost piles.