Composting grass clippings using freshly cut grass is an economical way to create nitrogen rich fertilizer. Fresh clippings have alot of moisture so you may want to let them dry out a bit before adding them to your compost heap. The freshly cut grass may stick together in clumps and this will inhibit the flow of oxygen in the heap. This can create a strong ammonia like odor, and the grass may develop a white mold. Dried out clippings aleviates these problems. At the bottom of your heap place a layer of browns. Browns are high carbon materials such as autumn leaves, broken up sticks, wood chips, even finely shredded newspaper. This brown matter will enable oxygen flow through the compost when added in layers between grass. You should alternate your layers, a layer of browns and a layer of grass clippings.
Aerate your compost heap to keep the oxygen flowing. Aerate the heap by turning the compost material with a garden pitch fork. When composting grass clippings it is important to aerate the compost on a regular basis.
To avoid the odors, souring and clumping of grass in your compost heap dry out the grass clipping by spreading them on a flat surface for at least a day prior to putting them in your heap.
Grasscycling is the easiest way to handle your grass clippings and use them to fertilize your lawn. Just leaving the grass clippings when they fall from the mower on the lawn is grasscycling. This saves money on lawn fertilizer and you won't need to bag and move your grass cuttings. You will need to make sure the grass is dry when you cut it so the clippings don't clump and dull the mower blade.
Clippings and Chemicals
If your lawn has recently been treated with herbicides or pesticides, you do not want to add this grass to your compost heap. Do not add this grass to your compost heap until the rain has washed off the chemicals. Adding lime to your compost heap will speed up the decomposing process, prevent the formation of mold, and the development of odors.