Compost turns yard waste like grass clippings into a nutrient-rich soil amendment to use in your garden beds and container plants. Composting requires both nitrogen- and carbon-rich organic waste to produce a suitable amendment. Grass clippings are high in nitrogen, so other organic waste is necessary for successful composting. The good news is that during the fall, all the leaves drying on your lawn provide the carbon you need for your endeavor. Keeping both your grass clippings and leaves out of your trash will save on disposal fees, too.
Dump your grass clippings in your compost bin. Spread them out and break up any clumps the wet clippings form with a garden fork or spade.
Dump in dried leaves or sawdust. Fill with enough leaves so that the ratio in the bin is two parts grass to one part leaves and/or sawdust. Use twigs or branches that have been fed through a wood chipper first if you are low on leaves.
Mix the grass with the other materials in the bin. Spread it out into a level layer after it is well mixed.
Sprinkle a half-inch layer of garden soil or finished compost on top the grass and leaf layer. This introduces the microbes that begin the composting process to the new heap.
Continue layering grass and leaves in the bin, topping with fresh soil and mixing the entire compost heap after each addition. Attempt to stay as close to the 2:1 ratio as possible.
Water the heap if it begins to dry out, since it won't compost when dry. Check moisture content by squeezing a handful of the grass and leaves---if a few drops of water squeeze out it is moist enough.
Turn the heap once a week, moving the clippings and leaves on the outside of the pile toward the center. The compost is ready when it is a rich brown, there is no recognizable organic matter in it, and it crumbles in your hand.