Compost Basics
(William Caxton, pioneer 15th century printer)
According to the Environmental Protection Agency (EPA), 1/4 of the food bought in America ends up in the waste stream -32 million tons per year. Of that, less than 3 percent gets composted. The rest ends up in landfills, where it slowly rots, emitting methane, a greenhouse gas 21 times more potent than carbon dioxide. The EPA reports that wasted food in landfills accounts for 1/5 of US methane emissions, the second largest human-related source of methane in the US.
Composting is not complicated. It happens naturally, without any help from us. We can speed up the process, however, by balancing carbon-rich materials (Browns) with nitrogen-rich materials (Greens), by turning the compost pile regularly for aeration and by keeping the pile wet (but not too wet.) Below is a list of readily available materials that can go into a compost pile.
Greens (nitrogen-rich)
- freshly cut grass
- plant prunings
- spent flowers
- coffee grounds
- kitchen scraps
- barnyard animal manures (cow, horse, chicken, goat, sheep, and rabbit. NEVER use dog, cat, or human manure/feces as they may contain pathogens or diseases that could be harmful.)
Browns (carbon-rich)
- black and white newsprint
- brown paper bags from grocery store
- torn/shredded carboard (brown boxes, brown packing tubes, toilet paper and paper towel rolls, tubes egg cartons)
- aged wood chips
- sawdust from untreated lumber (check with a lumber yard)
- straw
- dried grass
- dead leaves
Ingredients not suitable for composting are oil, grease, bones, fat, dairy products and diseased plants.
Cold Compost Pile
A pile which is made up of greens and browns and then left alone to rot in place for several months to several years.
Hot or Active Compost Pile
A pile which is made up of greens and browns and then turned and aerated often to incorporate air, water, and/or fresh ingredients. Requires more effort but often results in finished compost within a several weeks to a few months.
Sheet Composting or "Lasagna" Bed
A specific sort of compost pile in which green and brown materials are built up in layers over a present or future garden bed site.
Pit or Trench Composting
A method where you bury organic material directly in the ground, sometimes along side of plantings, in a shallow trench.
How to Build a Sheet Compost Bed
- Mark the area for your garden using a water hose or a long rope to get the desired shape. Do NOT remove sod or weeds.
- Cover the area you've marked with wet newspapers or flattened cardboard boxes (available free from most large stores). This is your weed barrier.
- Cover the weed barrier with organic material—leaves, grass clippings, straw, wood chips, etc. Wood chips are often available free from your city's sanitation department.
- Layer several inches of organic material on top of the weed barrier. Make sure you balance greens
- freshly cut grass
- plant prunings
- spent flowers
- coffee grounds
- kitchen scraps
- barnyard animal manures (cow, horse, chicken, goat, sheep, and rabbit. NEVER use dog, cat, or human manure/feces as they may contain pathogens or diseases that could be harmful.)
- black and white newsprint
- brown paper bags from grocery store
- torn/shredded carboard (brown boxes, brown packing tubes, toilet paper and paper towel rolls, tubes egg cartons)
- aged wood chips
- sawdust from untreated lumber (check with a lumber yard)
- straw
- dried grass
- dead leaves
- Water until the garden is the consistency of a damp sponge.
- Plant, plant, plant. Mulch, mulch, mulch.