Photo credit: “Real Compost,” Kessner Photography

In April, we posted a list of ten things you may not have known you could compost. So of course we had to do a list about things you didn’t know you can’t compost.

• Black walnut tree leaves and twigs (Releases substances that may be harmful to plants)
• Chemically treated yard trimmings (May kill organisms beneficial to composting)
• Coal or charcoal ashes (May contain substances that are harmful to plants)
• Cooked vegetables (This one is debatable)
• Dairy products (Attracts rodents, flies)
• Diapers (Unless they’re made from 100% compostable materials)
• Diseased or insect-ridden plants (Might transfer to other plants)
• Fats and oils (Attracts pests)
• Meat or fish bones/scraps (Attracts pests, odor problems)
• Pet wastes (May contain parasites, viruses)

Src: epa.gov/epawaste