Composting Basics: by Ken Freestone

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Materials provided by Ken Freestone, Master Composter
www.greenmichigan.org
ken@greenmichigan.org
Composting
Decomposer organisms work best with as varied a diet as you can feed them. The ingredients are all around us. Almost anything that once lived is a candidate for the compost, so try for lots of variety to get a good mix of textures and plant nutrients. In composting jargon, woody materials that are high in carbon (autumn leaves, paper, peat moss, sawdust, cornstalks, hay and straw, etc.) are called “brown” ingredients. Materials like garden refuse, manure, tea and coffee grounds, feathers, hair, and food scraps are high in nitrogen, or “green.” Some materials can actually be both: fresh grass clippings are “green,” for example, but dried grass is “brown.”

For successful results, you can use the simple rule that compost needs to be about half “brown” and half “green” by weight. Don’t bother to weigh your ingredients, though: an estimate is fine. Composting soon becomes a matter of instinct, like the cook who bakes without a recipe. If the pile doesn’t heat up, you know there’s not enough “green” in the mix, while a smell of ammonia means it needs more “brown.”

Materials to Use
Green
• Algae
• Bone meal
• Coffee grounds
• Eggshells
• Feathers
• Flowers
• Fruit and fruit peels
• Grass clippings (fresh)
• Hair
• Manure
• Seaweed
• Tea Leaves
• Vegetables and peelings
• Weeds

Brown
• Buckwheat hulls
• Coffee filters
• Corn cobs
• Cotton/wool/silk scraps
• Grass clippings (dried)
• Hay
• Leaves (dead)
• Paper
• Peat moss
• Pine needles
• Sawdust
• Straw
• Tea bags
• Wood chips
• Wood ash

This list is far from complete. Anything organic can, in theory, be composted — some more easily than others. But common sense suggests a few exceptions. The following materials may cause problems in a backyard compost pile.

Materials to Avoid
• pet wastes can contain extremely harmful bacteria
• meat, fish, fats and dairy products are likely to smell as they rot and may attract four-footed visitors
• insect-infested or diseased plants may persist in the compost
• materials contaminated by synthetic chemicals or treated with herbicides or insecticides should never be used
• weeds with mature seeds, and plants with a persistent root system (like crabgrass, ground ivy, or daylilies), may not be killed by the heat of the compost
• leaves of rhubarb and walnut contain substances toxic to insects or other plants so most people choose not to compost them.

Water
• Your compost pile should be as damp as a wrung-out sponge — moist to the touch — but no water should come out when you squeeze a handful.
Too dry?
• You can poke holes in the pile and water it from the top with a trickling hose. Better yet, pull the pile apart and rebuild it, wetting each layer as it goes on. Very fibrous materials such as dead leaves may need to be soaked in a bucket for an hour or two.

Too wet?
• A soggy pile should be turned so that clumps of material are broken up, letting air in and water out. If the compost is absolutely soaked, you can spread the materials to dry in the sun, or scatter peat moss through the pile as you rebuild it with the drier materials in the center