Materials to Use in Compost Piles
Our friends over at Organic Gardening Magazine provided us with this great list to simply a lot of the questions of what to put into a compost pile.
The general rule to a good compost pile is a 50/50 mix of brown and green materials. So if you add a green material, make sure your next layer in the compost pile is a brown material. Green materials are high in nitrogen and brown materials are high in carbon.
Green Materials | Brown Materials |
Aquarium Water, Algae & Plants | Brown garden debris |
Chicken Manure | Black-and-White Newsprint & Office Paper |
Dead Houseplants | Cardboard |
Fresh Grass Clippings | Hedge Prunings & Twigs |
Green Garden Debris | Leaves |
Horse Manure | Pine Needles |
Manure from Pet Rabbits and Rodents | Sawdust |
Vegetable Kitchen Scraps | Straw |
Weeds | Wood Ash |
Source: Organic Gardening Magazine
Also, to keep your compost pile truly organic, make sure your items came from a source free of pesticides, containments and toxins!
Desert Greenhouse Guideline: Another source for green material for composting is Coffee Grounds. Desert soil is typically alkaline and coffee grounds are acidic. Check out Starbucks Grounds for Your Garden program. |
Questionable Compost Materials
Generally speaking, if you are not sure if you should put something in a compost pile, don't. Here is a list of compost materials to help answer some of those questions.
Material | Concern |
Carnivore Manure | Dog, cat, pig, and reptile manures (and associated bedding) may contain parasites or dangerous pathogens that are harmful to humans, particularly pregnant women, children, and people with compromised immune systems. Never add them to your compost. |
Cloth | Natural-fiber cloth doesn't add any benefit to the compost pile. Consider using burlap bags under wood chips to prevent weeds instead. |
Cow Manure | Cow manure may contain E. coli O157:H7, a very dangerous pathogen that can cause severe illness and even death. "It's hard to meet time and temperature requirements to kill pathogens in a home compost pile," says soil scientist Craig Cogger, Ph.D. We don't recommend adding it to home compost ever because of the health risk. But if you're tempted to use it, you must wait at least four months after you add it to your soil before you can harvest, to make sure the pathogens are no longer active. Wear gloves when handling manure and wash your hands thoroughly. |
Diseased plants | Diseased plants must be disposed of in the garbage or burned. Adding them to compost could spread the disease. |
Dryer Lint | Dryer lint may contain synthetic fibers that will never decompose. Even natural-fiber lint adds no benefit to compost. |
Glossy Paper | Paper, especially glossy paper, printed with colored ink, may contain heavy metals. Black-and-white newspaper is safe. |
Gypsum | Gypsum board scraps could contain paint and other undesirable toxins. |
Hair | Human and pet hair can be added in small amounts, if you keep in mind that it breaks down slowly, mats easily, and sheds water. |
Meats, dairy products, bones, and fish | Meats, dairy products, bones, and fish decompose slowly, smell, and attract animals. |
Sawdust | Sawdust must be used in moderation, because it breaks down very slowly and can lock up nitrogen. Never use sawdust from treated or painted wood. |
Unknown Sources of Clippings | Materials from the side of the road, including grass clippings and leaves, could contain petroleum residues (such as oil), toxins, and nonbiodegradable materials. |
Vacuum Bags | Vacuum bags may contain synthetic carpet fibers and other nonbiodegradable items. |
Wood Chips | Wood chips should be used as mulch around ornamentals because they break down so slowly. |
Source: Organic Gardening Magazine
When Things Go Wrong
Remember, a good compost pile should not smell foul. If you find your pile has an odor, is attracting flies or is slow to decompose, there is an issue that needs to be addressed.
Concern | Possible Cause & Solution |
Pile is dry | A dry pile will be slow to decompose, there may be too much wood material or it just need to be wet down. Turn the compost pile and add enough water to make it the consistency of a wrung out sponge. |
Pile is too wet | An overly wet will be starved of oxygen (essential to the decomposition process) and may begin to smell. Add some brown materials and turn the pile. |
Pile has an odor | There is either too much green material or is too wet. Add more brown material and turn the pile. |
Pile is attracting flies | Make sure to cover organic waste such as manure and kitchen scraps, both of which attract flies. |
Pile is not composting | If your pile is moist and still not decomposing, you most likely need to add more green material and turn the pile. |
Desert Greenhouse Guideline: Keeping a compost pile moist can be a challenge for some gardeners in the hot, dry desert climate. Be sure to check often that your compost pile has enough moisture to keep the compost process going. |
Finished Product
When you compost pile has reduced to one-third its original size and the internal temperature has dropped, that is a really good indicator your compost is ready to use! Use a sifter to removed any material that is not composted and use it in the next pile.
Sources:
- Compost Materials courtesy of Organic Gardening Magazine