...from MNN:



NEVER COMPOST:

Bread products: This includes cakes, pasta and most baked goods. Put any of these items in your compost pile, and you've rolled out the welcome mat for unwanted pests.


Cooking oil: Smells like food to animal and insect visitors. It can also upset the compost's moisture balance.


Diseased plants: Trash them, instead. You don't want to transfer fungal or bacterial problems to whatever ends up growing in your finished compost.


Heavily coated or printed paper: This is a long list, including magazines, catalogs, printed cards and most printed or metallic wrapping paper. Foils don't break down, and you don't need a bunch of exotic printing chemicals in your compost.


Human or animal feces: Too much of a health risk. This includes kitty litter. Waste and bedding from non-carnivorous pets should be fine.


Meat products: This includes bones, blood, fish and animal fats. Another pest magnet.


Milk products: Refrain from composting milk, cheese, yogurt and cream. While they'll certainly degrade, they are attractive to pests.


Rice: Cooked rice is unusually fertile breeding ground for the kinds of bacteria that you don't want in your pile. Raw rice attracts varmints.


Sawdust: So tempting. But unless you know the wood it came from was untreated, stay away.


Stubborn garden plants: Dandelions, ivy and kudzu are examples of plants or weeds which will probably regard your compost heap as a great place to grow, rather than decompose.


Used personal products: Tampons, diapers and items soiled in human blood or fluids are a health risk.


Walnuts: These contain juglone, a natural aromatic compound toxic to some plants.