What Not to Compost - The OUT List!

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