Organic material makes up about 58 percent of what Denver residents send to the landfill every year. These items can be composted, which is the controlled decomposition of organic materials by microorganisms. This process results in compost, a crumbly, earthy-smelling, nutrient-rich, soil-like material. 


Essential Concepts:

Compost contains both carbon and nitrogen sources, which can be simplified as browns for carbon (e.g., leaves, straw, woody materials) and greens for nitrogen (e.g., grass and food scraps). Adequate sources of carbon and nitrogen are important for microorganism growth and energy. 

 Organic materials are broken down through the activities and appetites of various invertebrates that will naturally appear in compost, such as mites, millipedes, beetles, sowbugs, earwigs, earthworms, slugs, and snails. These microorganisms need adequate moisture and oxygen to degrade the organic materials in the most efficient manner.

Microbes in the pile create considerable heat and essentially "cook" the compost. Temperatures between 90 and 140 degrees Fahrenheit are common in properly maintained compost piles, but may not reach these levels in backyard compost piles. These high temperatures are necessary for rapid composting as well as for destroying weed seeds, insect larvae, and potentially harmful bacteria. When the compost is finished, it has a crumbly texture throughout the pile.

Vermicomposting is a method of composting that uses a container of food scraps and a special kind of earthworm known as a red wiggler. Over time, the food is replaced with worm droppings, a rich brown matter that serves as an excellent natural plant food.  For more information on what to feed worms and a list of worm vendors visit  the page Compost Bins & Worm Vendors.

What Can be Composted in a BACKYARD bin?

Below is a list of some items that can be put in a BACKYARD composting bin. Some food products should not be included because they can attract pests or compromise the quality of the compost. This list is not meant to be all inclusive:

YES	NO
Fruit and vegetable scraps Egg shells Coffee grounds with filters Tea bags Fireplace ash Leaves Grass Straw Yard clippings Vacuum cleaner lint Wool and cotton rags Sawdust Newspaper	Meats Dairy foodsFish scraps Bones Fats Oils (including peanut butter and mayonnaise) Grease Pet excrement Diseased plants Medical waste

Troubleshooting:

If you supply the proper conditions (volume, surface area, moisture, air and variety of materials), you should have little difficulty maintaining your compost system. Occasionally, though, problems occur in any biological system. They usually can be dealt with fairly easily by following these tips: