Air is needed for composting bacteria to thoroughly break down plant material. Aeration can be accomplished by regular turnings of the compost pile, preferably weekly. A pitch fork or spading fork can be used to turn a pile.
Plastic perforated pipes can be laid throughout the pile to increase air movement.
If the temperature of a pile drops, the compost needs either moisture or aeration.
Ideal compost sizes range from 3x3x3 to 5x5x5. Smaller piles will not generate the heat necessary for plant material to decompose. Larger piles are harder to manage and may not decompose uniformly.
Fertilizer is needed for organic matter to properly decompose. Aerobic bacteria use nitrogen to multiply and break down the organic material.
A couple cups or handfuls of a complete garden fertilizer such as a 10-10- 10, 12-12-12 or 15-15-15 should be added to the compost pile regularly.
Avoid overfertilizing which can kill the decomposing bacteria.
Grass clippings can be composted if weed killers or herbicides have been applied. Herbicides on the market will decompose within a matter of months and not affect the final product.
Lawn weeds, like other plant material, will decompose in a compost pile. Weeds sprayed with herbicides can also be composted with no fear of plant damage from the finished compost.
Old compost recipes called for the addition of limestone when creating the pile. Research has shown that the finished compost has a pH approaching 7. Limestone needs only be added if the compost contains acidic plant material such as evergreen needles.