To break down effectively, compost ingredients need a good balance between “green” (fresh) and “brown” (dried or aged) ingredients. The green ingredients tend to have a higher nitrogen content, while the brown ingredients provide a higher percentage of carbon.
The simplest and most efficient compost heap consists of little more than manure and straw. But you can also compost just about anything organic, including:
- Manure from cows, horses, rabbits, bats, poultry
- Weeds you’ve pulled from the garden (toss any diseased plants)
- Dead flower bouquets
- Dryer lint
- Paper products: cardboard, newspaper, shredded papers, paper towels, cardboard egg cartons, cardboard tubes, coffee filters
- Hair
- Seaweed (rinse off the salt first)
- Coffee grounds and tea leaves
- Egg shells
- Fruit and vegetable scraps and trimmings
- Leftover rice or pasta (plain, without oil or meat flavorings)
- Stale bread or cereal
- Wood chips
- Small twigs
- Wood or pure charcoal ashes (not ashes from charcoal briquets, which may contain borax, coal and other chemicals toxic to plants)
- Dead leaves
- Pine needles (easiest if you cut them or shred them first; they’re acidic, so don’t overuse unless you have alkaline soil)
- Fresh or dried grass clippings
- Straw
- Used vacuum cleaner bag (with contents)
- Old rags or cotton or linen clothing (cut or shred them into small pieces first).
Do not add manure from dogs, cats, pigs or people (all of which can carry parasites and diseases dangerous to humans). One exception is “humanure” from a composting toilet.
While you won’t read recommendations for it in many of the community-sponsored composting publications, urine (which does not carry the germs that solid wastes do) is rich in nitrogen and considered good for the compost pile. Some avid composters even use old-fashioned chamber pots at night so they can dump the contents on the compost heap. This practice may not appeal to most people, but there’s no harm in it and one can argue that it’s a more ecologically sound way to get rid of pee than using all that water to flush it down.
Do not compost:
- Meat and poultry scraps. They smell bad, attract critters and probably won’t decompose fully.
- Fish scraps, unless you have a way to keep animals out of your compost pile. While fish is an excellent fertilizer, rotting fish stinks and is a magnet for animals, both wild and domestic. (One of my more memorable pet bonding experiences? Being greeted by a dog that had just dug up three-week-old fish scraps. Ugh.)
- Oils and other fats. The average backyard compost pile will not get hot enough to break these down. And animal fats will attract pests.
- Inorganic materials (metal, rock, etc.). This should come as no surprise, but they don’t decompose. And they may be toxic to plants.
- Tree limbs or other large items, unless you chip or shred them first
- Hazardous chemicals, for obvious reasons
- Soap, salt or other substances that may kill bacteria. You don’t want to destroy those nice bacteria that are eating all that garbage and turning it into garden soil for you.
- Diseased plants, or weeds that have gone to seed. The pile may not get hot enough to kill off the diseases and weed seeds.
If you’re interested in learning more about how to build a proper compost pile, check out Rod Turner’s excellent ebook, The World’s Best Compost, which takes a very thorough look at the topic.
