Composting Cautiously: What Not to Add to Your Compost Pile and Why

Composting Cautiously: What Not to Add to Your Compost Pile and Why

Composting is a fantastic way to reduce waste, enrich your garden soil, and contribute to a more sustainable lifestyle. However, not all materials are suitable for the compost pile. Understanding what not to compost is crucial to maintain a healthy and efficient composting process.

In this article, we'll explore common items you should avoid adding to your compost and explain why they don't belong. We avoided mentioning obvious items that you shouldn't compost such as paint, motor oil, and so forth.

1. Meat and Dairy Products:

Why not: Meat and dairy products can attract unwanted pests like rodents and flies, and they tend to decompose slowly, leading to unpleasant odors. The high fat content can also disrupt the balance of your compost pile.

2. Diseased or Pest-Infested Plants and Plant Parts:

Why not: Plants that have succumbed to diseases or pests should not be composted because the pathogens or eggs of pests can survive in the compost, potentially infecting future crops when you use the compost in your garden.

3. Pet Waste:

Why not: Pet waste, including feces and litter, can contain harmful pathogens and parasites that are not fully eliminated during the composting process. It's best to dispose of pet waste separately.

4. Synthetic Materials:

Why not: Materials like plastic, metal, glass, or any non-biodegradable items should never be added to your compost. They won't break down and can contaminate your compost with toxic chemicals.

5. Weeds with Mature Seeds:

Why not: Weeds with mature seeds can survive the composting process and sprout in your garden when you use the compost. It's best to dispose of these weeds in another way to prevent them from spreading.

6. Glossy or Coated Paper:

Why not: Paper with a glossy finish or coated in ink or chemicals should be avoided. These materials may not break down effectively and can introduce toxins into your compost.

7. Large Branches or Woody Stems:

Why not: Large branches and woody stems decompose slowly and can impede the composting process. It's best to chop or shred them into smaller pieces before adding them to your compost.

8. Coal or Charcoal Ash:

Why not: Ash from coal or charcoal may contain toxins and heavy metals that are harmful to plants and the environment. Wood ash from untreated wood is generally safe in moderation.

9. Fats and Oils:

Why not: Grease, cooking oils, and fatty foods can create unpleasant odors, attract pests, and disrupt the balance of your compost pile. It's best to dispose of these materials in other ways, such as recycling or proper disposal.

10. Synthetic Chemicals or Herbicides:

Why not: Any materials treated with synthetic chemicals or herbicides should not be composted as they can harm the beneficial microorganisms in your compost pile and potentially contaminate your garden soil.

11. Colored or Glossy Cardboard:

Why not: Cardboard boxes treated with colored inks, glossy finishes, or adhesives may contain chemicals that are not suitable for composting. Stick to plain, untreated cardboard.

12. Large Quantities of Citrus Peels:

Why not: While citrus peels can be composted in moderation, adding too many can make the compost too acidic, which is not ideal for most garden plants.

13. Walnuts

Why not: Walnuts contain a natural compound which is toxic to some plants, called juglone. (Source: Treehugger)

By avoiding these materials in your compost pile, you can maintain a healthy and productive composting system while reducing the risk of pests, diseases, and unwanted chemicals in your garden. Composting responsibly not only benefits your garden but also contributes to a more sustainable and eco-friendly lifestyle.

Earth Smart Solutions offers a number of products to help with your composting. Learn more here.

For a list of items that you can add to your compost, check out our blog, "Green to Gold: Surprising Items You Can Compost to Enrich Your Garden and Reduce Waste".


howstuffworks, 75 Things You Can Compost, But Thought You Couldn't

Ocean Wise, 16 Surprising Things You Can Compost in Your Green Bin

Treehugger, 12 Things You Should Never Compost


Please note that this list is not inclusive. There are likely more things that can NOT be composted that are not listed.