Composting: the rotten truth Anne Kolaczyk Purdue University Master Gardener ©2006Anne Kolaczyk

Composting Composting is the transformation of organic material (plant matter) through decomposition into a soil-like material called compost. Invertebrates (insects and earthworms), and microorganisms (bacteria and fungi) help in this transformation.

Kinds Bin composting Tumbler composting Sunken pail composting Sheet composting Anaerobic composting Vermicomposting Bin composting—what most people do Tumbler commercial bin that rotates when turned every day, produces compost in about a month small size need multiple tumblers or you have a stretch when you can’t compost good for kitchen waste Sunken pail Good for kitchen waste 5 gal pails with drainage holes in the bottom buried almost to top and covered When full, throw some dirt in and close up By the time you fill up a second bucket, the first should be done Smelly when open Sheet composting 4 to 6 inches over garden in fall spade into soil in the spring Mulching is sheet composting at its simplest Digging holes and burying waste is sheet composting Anaerobic composting airless, can be done in plastic bags, smelly if bag breaks Good for small quantities Add a few handfuls of dirt Leave in sun and turn every few weeks Vermicomposting using worms Superior nitrogen-rich compost Secrete calcium carbonate which regulates the soil’s pH Enzymes they secrete promote growth

Why do it Environmentally responsible Saves money Learning tool Keeps biodegradable waste out of landfills and sewage plants Alternative to burning Gives you a vibrant garden without chemical fertilizers Saves money Learning tool

What it involves Adding ingredients Maintaining proper temperature Turning Maintaining moisture Harvesting Some methods require fewer of these steps as the system itself handles the chore—no turning is necessary with buried pail; if your bin pile is big enough, the temp will be fine.

“backyard composting” Bin composting “backyard composting”

Composting bins Ready made Homemade Bin-less pile

Ready made Expensive Limited capacity Good if space is an issue Good for small spaces

Homemade Three bins are best One to fill One that’s “cooking” One to turn others into or to draw from

Bin-less pile Just a pile with no partitions Hard to maintain sufficient depth to achieve high enough temperatures Easy and nothing to build Moveable Need a cubic yard to get interior hot enough to kill off pathogens and weed seeds.

What you can compost Yard waste Kitchen scraps Newspaper Cardboard

What not to compost Meat scraps Bones Dairy products Pet waste Diseased plants Invasive weeds Meat scraps and bones attract animals. Smell and can take a long time to decompose. Same with dairy products. Pet waste may carry pathogens. There is some controversy about whether pet waste can be composted safely. Might also avoid diseased plants and invasive weeds. The temp of your pile might not be high enough to kill them off.

C:N ratio Should be 30 parts carbon to 1 part nitrogen by weight Grass Clippings 19:1 Leaves 40:1 Equal weight of each would give you approximately 30:1 ratio for pile

What’s what Green (Nitrogen) Brown (Carbon) Grass clippings Plant clippings Fertilizer Coffee grounds Brown (Carbon) Leaves Dirt Grocery bags Bird seed hulls Wood chips

C:N ratio, my take Whatever!

Care of compost Passive Active Let sit Takes months and months Turn often Keep moist (H2O 40-60% of weight) Have proper ratio of C:N (30:1) 2-6 weeks (depending on ingredients)

Let’s get real Concerns Solutions I don’t have room Use commercial bin It takes too long Maintain proper conditions Cut up large pieces It smells Not if you maintain C:N ratio Temps too low to kill diseases, fungi, weed seeds Use local community composting facility for problem pieces, compost the rest Attracts animals Bury food waste in center

Uses Early stages as mulch Later stages for soil amending Keeps weeds from growing Helps retain moisture Beneficial minerals go into soil Later stages for soil amending Enriches soil Helps with moisture retention Removes/reduces need for chemical fertilizers that leach into our ground water

What method is right for me??? How much space do I have? Is it indoor or outdoor or both? What do I want to compost? How much waste do I have a week? How and where do I want to use the compost? How much time can I spend on it a week? What’s my ewww! factor? How committed am I to composting?

Resources Purdue Extension office Library Internet

Anaerobic Vermi Sheet Pail Tumbler Bin composting Just do it!