Making Compost

Compost is easy to make. Essential components are organic matter, water, air, and nitrogen. To make compost, simply mix organic materials such as leaves, weed and other garden debris into a pile or bin. Moisten the materials as they are placed into the bin. Researchers suggest soil or compost starters are not essential, as the organic matter naturally contains the decomposing bacteria.

Oxygen and water are critical elements in the composting process. To speed decomposition, materials should be moistened as they are placed in the compost bin. Keep the pile moist, but not water logged. Avoid over chopping composting materials or packing of the pile, which restricts oxygen infiltration.

Large compost piles, up to 6 feet across will process faster than small piles The large piles allow for better heating, which drives the process. Active compost will heat to 120 to 160 degrees in the center of the pile. This desired heat stimulates the bacterial process and helps sanitize the interior of the pile. In Minnesota, avoid turning compost piles in the fall. This allows valuable heat to escape, and may stop the processing as we move into the cold winter. Small piles, which freeze in the winter, may need turning in the spring to start the pile processing again.

Composting materials high in carbon, like fall leaves, straw, sawdust and wood chips, needs extra nitrogen to feed the bacteria, which do the processing. Access INFO-U message number 279 for special instructions on Composting Fall Leaves.

Compost is ready to use when it has shrunk to one-half its original volume, has lost the identity of the original material and has a pleasant earthy smell.

For more information on composting, contact your local University of Minnesota Extension Service office.