The following items should not be used in composting.

Leave Out & Reason Why
Black walnut tree leaves or twigs
      Releases substances that might be harmful to plants
Coal or charcoal ash
      Might contain substances harmful to plants
Dairy products (e.g., butter, egg yolks, milk, sour cream, yogurt)
      Create odor problems and attract pests such as rodents and flies
Diseased or insect-ridden plants
      Diseases or insects might survive and be transferred to other plants
Fats, grease, lard, or oils
      Create odor problems and attract pests such as rodents and flies
Meat or fish bones and meat scraps
      Create odor problems and attract pests such as rodents and flies
Pet wastes (e.g., dog or cat feces, soiled cat litter)
      Might contain parasites, bacteria, germs, pathogens or viruses.
Yard trimmings treated with chemical pesticides & fertilizers.
      Might kill beneficial composting organisms

Only use all natural, biodegradable materials when composting. Remember, the end product should be completely organic.

What Not to Compost