Expert composters desiring to produce finished compost faster turn to compost activators and accelerators to jump-start the microbial activity. These activators and accelerators operate by simultaneously increasing the number of decomposing bacteria at work on your compost waste and providing extra nitrogen, which encourages bacterial growth and reproduction. Another proven technique that encourages faster decomposition is increasing the oxygen available in your compost. According to the University of Illinois Cooperative Extension, higher oxygen levels in compost help the compost microbes grow more quickly and consume waste faster.
Take extra time to prepare your compost waste for decomposition. Tear large pieces of waste, such as cardboard and newspaper, into long, thin strips that measure no more than 1 ½ inches wide. Break large sticks into short pieces, and saw thick branches into thin discs that are less than 2 inches thick. Chop large fruit and vegetables, such as pumpkins or melons, into small pieces with a shovel. Shred dead leaves by driving over them with a push mower.
Alternate 3- to 4-inch layers of carbon-rich waste (dry, brown materials, such as dead leaves, newspaper, cardboard, sawdust and sticks) with nitrogen-rich waste (wet, green materials, such as fresh grass clippings, animal manure, fruit scraps and vegetable peels). Sprinkle a ½-inch-thick layer of compost activator in between your layers of carbon and nitrogen waste. Opt for organic compost activators, such as plain topsoil, cow manure or finished compost, which---unlike chemical activators---provide protein for the decomposing microorganisms, according to the University of Illinois Cooperative Extension.
Build your compost heap into a pile that measures no less than 3-feet-by-3-feet but no more than 5-feet-by-5-feet; these dimensions help sustain hot composting temperatures that decrease composting time. Make sure the height of your compost heap matches its width. Cover your compost pile completely with a plastic tarpaulin to help contain the composting heat. Dampen your entire compost pile with enough water to make it the consistency of a wrung-out sponge.
Aerate your compost at least once every week, more frequently if you want your compost to decompose even more quickly. Scoop compost waste from the center of your pile with a garden fork. Shovel compost materials from the edges of the heap to the center. Touch the compost each time you aerate the pile to ensure that it's still about as wet as a wrung-out sponge; add extra water, if necessary. Depending upon how frequently you turn the pile, you can expect finished compost in two weeks to four months.