"One part green and two parts brown, Makes the compost turn to ground.  Add some water and some soil.  Turning is the only toil."

A backyard compost pile is made by mixing dry leaves (brown, high carbon material) with grass clippings (green, high-nitrogen material), soil and water.  Mix periodically to add air.  Chopping or shredding the materials speeds the process.  This recipe sets up an ideal environment for nature's decomposers to work.

• Home Composting Recipe (pdf)
• Home Compost Bin Options (pdf)
• Worm Bin Composting (pdf)

1. Mix one part green material with two parts brown materials.

GREEN MATERIALS
with high nitrogen content include:

BROWN MATERIALS
with high carbon content include:

Grass, weeds and non-woody garden prunings
Spent flowers, bouquets
Farm animal manures (cow, horse, chicken, sheep)
Fruit & vegetable garden scraps
A sprinkling of blood meal or cottonseed meal
Use as 1/3 of the compost pile, or as "1 part green"

Dry leaves (create a stockpile in fall)
Dead brown plants or potted plants
Straw, sawdust
Pine needles
Finely chopped woody brush, corncobs
Use as 2/3 of the pile, or as "2 parts brown"

2. Sprinkle a shovel-full of soil or mature compost every six inches to provide the microorganisms necessary for the decomposition  process.

3. Add water to keep the pile as damp as a wrung-out sponge.

4. Mix or turn periodically with a garden fork.  Microorganisms need oxygen and small particle size.  The more often you turn the pile, the quicker it breaks down.

Notes: Do not add meat, dairy products, cooked produce, diseased plant material, dog or cat wastes to a backyard pile.  A compost pile made with mostly green materials ( i.e., grass) may become soggy and release unpleasant odors.  If this happens, break the heap apart and rebuild it, adding layers of brown materials and turn more often to dry out the pile.  Place diseased plants and weed seeds out for municipal collection, so they can be decomposed in a "hot" environment.

What is Compost?

The recycling and decomposition of plant materials is called composting. Nature's recycling system is simple. Leaves and grasses that fall to the ground provide a home and food supply for nature's recyclers — bacteria, worms and insects. These organisms feed on the materials, turning it into composted organic material. Through decomposition, nutrients essential to plant growth are released into the soil and are
absorbed through the roots. When you remove yard waste from the landscape where it was produced, you deprive plants of their own natural fertilizing source.

A good size for a home compost pile is three to four feet high by three to four feet wide. This size is large enough to hold heat and still small enough for good air flow. Locate your pile close to your garden and a water source and away from wooden structures and your neighbors. Yard wastes can be simply raked into an inconspicuous area on your lot.  A tidier method uses simple structures that confine the pile.

An open pile blends into the landscape of a garden or semi-wooded site.

Plastic structures do not decompose over time.  These small units fill up quickly.

Four wooden pallets may be tied together to build a free recycled unit.

Multiple units separate fresh yard wastes in one bin from actively-composting materials in another.  A third unit holds mature compost until used.

Twelve feet or more of chicken wire or snow fencing can be tied into corral.  Optional hooks or clips make it easy to open.

Enclosed units prevent access by small animals and hold in odors.  They are designed to compost food wastes underground.

A public display of home-built and commercially available bins can be seen at the Leslie Science Center, 1831 Traver Road. The site was made possible with a Michigan Solid Waste Alternatives Program grant from the Michigan Department of Environmental Quality in cooperation with the City of Ann Arbor and Project Grow Community Gardens. More information on composting is available from: the Washtenaw County Coop Extension Service,222-3853, Project Grow, 996-3169; the Ecology Center, 971-3186; and your local public library.

Uses of Mature Compost

Once yard wastes have fully decomposed, the compost appears as a rich, dark, crumbly material, also called humus.  Compost contributes to good soil structure, which allows soil to retain nutrients, moisture and oxygen for long periods of time. Compost helps lighten heavy clay soils and helps retain moisture in sandy environments.

Several inches of humus may be added to flower and vegetable gardens in the spring or fall. Similar to peat moss, humus may be used when starting seedlings and planting trees and shrubs. Screened humus may be used as a top dressing for lawns. Spread up to one inch of compost over the lawn in spring and rake in gently. Mulching around plantings with humus helps prevent the soil from drying out, provides nutrients, prevents erosion and helps modify soil temperatures.

Mulch Yard Waste Directly

Grass clippings, shredded leaves, hay and woodchips may be also used as composting mulches without going through a compost pile cycle. Spread plant materials around plants, trees and shrubs, keeping the mulch a few inches away from the stem of plants to avoid rot. Leave grass clippings and mowed leaves on the lawn to naturally decompose.  The clippings will recycle nitrogen and other nutrients back into the soil and reduce the need for fertilizers.