Types

• Compost requires a mixture of ingredients providing nitrogen and carbon. These ingredients are commonly called "greens" and "browns," and not surprisingly, fresh grass clippings fall into the nitrogen-rich "green" classification. In order to produce compost, you need to mix your green grass clippings with a source of carbon. (See References 1)
  
  

Time Frame

• The time to produce compost depends on many factors. The fastest method of producing compost is called "hot" composting and involves overloading nitrogen to boost bacterial reproduction, causing a faster breakdown of the materials. The Oregon State University Extension website recommends adding two parts brown ingredients for every one part green. For example, you might add two bags of dead leaves for every bag of grass clippings. (See References 2) Hot composting produces finished compost in about eight weeks. (See References 1)
  
  

Considerations

• Hot composting also requires frequent turning to aerate the pile and distribute moisture. If you don't have time or the desire to do this, your grass clippings will end up as compost eventually; it will just take months rather than weeks. Compost expert Barbara Pleasant urges gardeners not to overthink compost. More thought and attention only speeds up the process. (See References 3)