Composting

*Free Composting classes available provided by the Ashland Conservation Commission and Recology Ashland Sanitary Service. Go to http://www.ashland.or.us/CCBIndex.asp?CCBID=193 for more information.

Each year, more than 45,000 tons of yard waste go into our area trash. That’s almost 20% of all the trash that goes to our landfill. What a waste, when most of that can be recycled…through composting.
By composting at home, you can help relieve the burden at our landfill. So, do something good for the earth. Put yard and food waste back where it belongs.

How Does Composting Work?

Thanks to simple decomposition, nature “recycles” plant wastes into a rich soil additive called compost. It is a dark, crumbly soil-like material that can be used as a mulch, top dressing or soil amendment. Like good cooking, composting is part science, part art. Even the first-time composter can make good quality compost. Without getting too technical, here’s a review of what’s involved.

Materials

Anything that was once alive will naturally decompose. However, some organic wastes should not be composted at home:

DO Compost These Items:

Grass clippings
Leaves
Flowers
Old plants
Old potting soil
Twigs
Annual weeds
Vegetable scraps
Coffee filters
Tea bags

DO NOT Compost These Items:

Diseased plants
Weeds with seeds
Invasive weeds(like quack grass & morning glory)
Bread and grains
Meat or fish parts
Dairy products
Grease, oil, or oily foods

Biology

Bacteria start the process of decaying organic matter. They are the first to break down plant tissue and also the most numerous and effective composters. Fungi and protozoans soon join the bacteria and, somewhat later in the cycle, centipedes, millipedes, beetles, and worms finish what the bacteria started.

Surface Area

If the microbes have more surface areas to feed on, the materials will break down faster. It’s like a block of ice in the sun…slow to break down when it’s large, but break into smaller pieces and it melts quickly. Chopping your garden debris with a machete, or using a chipper/shredded or lawnmower to shred materials will help them decompose faster.

Time & Temperature

The most efficient decomposing bacteria thrive in temperatures between 110 and 160 degrees F. Thus, the hotter the pile, the faster the decomposing. If you achieve a good balance of carbon and nitrogen, provide lots of surface area within a large volume of material, and maintain adequate moisture and aeration, the temperature will rise over several days.

Volume

A large compost pile will insulate itself, trapping the heat generated by microbial activity. A 3′ by 3′ by 3′ pile (1 cubic yard) is considered minimum size for hot, fast composting. Piles wider or taller than 5 feet don’t allow enough air to reach the microbes at the center.

Moisture & Aeration

Most life on earth needs a certain amount of water and air to survive. The microbes in the compost pile function best where the materials are as damp as a wrung out sponge and have many air passages. Extremes of sun or rain can adversely affect the balance of air and moisture in your pile. The air in the pile is usually used up faster than the moisture, so the materials must be “turned” or mixed up occasionally to add air that will sustain high temperatures and control odor.

All organic materials contain carbon and nitrogen in varying ratios (C:N). Carbon in brown leaves and woody wastes provides energy, while nitrogen in green grass and vegetable scraps provides protein for cell development. A C:N ration of 30:1 is considered ideal for composting. This balance can be achieved by mixing roughly two parts grass clippings (C:N=2:1) with one part brown leaves (C:N=60:1). Making layers of green and brown materials can be useful in arriving at these proportions, but a complete mixing of ingredients is preferable for composting. Though a C:N ration of 30:1 is ideal for hot, fast composting, higher ratios (with more carbon materials) will work adequately for slower composting.