12 Things You Should Never Compost

things to never compost

Treehugger / Hilary Allison 

Remember the good ol' days — back when we only had one bin for trash? In retrospect, those days were actually more wasteful than good. We sent things to the landfill that might have nourished our yards, and buried them side-by-side with materials that should have been reclaimed and put back in the production chain.

Today, most of us have a compost bin. They're great for reducing curbside trash, but not everything is suitable for those bins.

We've rounded up a list of things people mistakenly try to compost. We chose items generally avoided by experienced compost gurus. Ready? To the bins!

1. 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.

2. Cooking Oil

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

3. Diseased Plants

black spots on leaf
Leaves or branches from a diseased plant can ruin your entire compost pile. Manfred Ruckszio/Shutterstock

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

4. 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.

5. Human or Animal Feces

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

6. Meat Products

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

7. Dairy Products

Cheese platter
Just like us, lots of rodents love cheese and can get into your compost to eat it. Igor Dutina/Shutterstock

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

8. 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.

9. Sawdust

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

10. 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.

11. Used Personal Products

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

12. Walnuts

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

It should be pointed out that there are a minority of people who compost practically everything, including items on this list. We've stuck to composting best practices, omitting things that obviously don't belong in the garden (paint, motor oil, etc.). We've also skipped disputed or iffy items, such as dryer lint and highly acidic citrus fruit.