What NOT to Put in Compost: A Comprehensive Guide to Successful Composting

Composting is a fantastic way to reduce waste, enrich your garden, and contribute to a more sustainable lifestyle. But before you start tossing everything into your compost bin, it's crucial to understand what materials are compostable and, more importantly, what not to put in compost. Adding the wrong items can attract pests, create unpleasant odors, slow down decomposition, and even introduce harmful pathogens into your garden soil. This comprehensive guide will walk you through the do-not-compost list, providing you with the knowledge to create healthy, thriving compost every time.

Why Knowing What NOT to Compost Matters

Imagine meticulously building a compost pile, only to discover it's now a breeding ground for flies or reeks of ammonia. Or worse, you unknowingly spread diseases to your precious tomato plants because you composted contaminated food scraps. It's not a pretty picture, is it? Knowing what not to include in your compost is just as essential as knowing what to add. Understanding the no-go items will:

• Prevent foul odors: Some materials decompose anaerobically (without oxygen), leading to putrid smells that can bother you and your neighbors.
• Discourage pests: Certain foods and materials attract rodents, insects, and other unwanted visitors to your compost bin.
• Avoid harmful pathogens: Meat, dairy, and diseased plants can harbor bacteria and pathogens that can contaminate your compost and pose a risk to your health and garden.
• Maintain proper decomposition: Some items simply don't break down easily and can slow down the composting process, while others can disrupt the delicate balance of microorganisms essential for decomposition.
• Protect your plants: Introducing harmful chemicals or toxins through your compost can damage or even kill your plants.

The Definitive List of What NOT to Put in Compost

Let’s get down to the specifics. This detailed list outlines the items that are generally considered unsuitable for composting. Keep in mind that composting is a science and an art, and some of these guidelines may vary depending on your composting method and personal preferences. However, this list provides a solid foundation for beginners and experienced composters alike.

1. Meat, Poultry, and Fish Scraps

Raw or cooked meat, poultry, and fish scraps should never be added to your compost pile. These items:

• Attract pests: The strong odors of meat and fish are highly attractive to rodents, flies, raccoons, and other animals.
• Cause unpleasant odors: As meat decomposes anaerobically, it releases foul-smelling gases like ammonia and sulfur compounds.
• May contain pathogens: Raw meat can harbor harmful bacteria like Salmonella and E. coli, which can survive the composting process and contaminate your garden.

Exception: If you have a hot composting system (reaching temperatures of 130-160°F for extended periods), you *mightbe able to compost small amounts of meat scraps. However, it's generally not recommended for home composters due to the risk of incomplete decomposition and pathogen survival. Stick to vegetable scraps, coffee grounds, and yard waste for the safest and most effective composting.

2. Dairy Products

Similar to meat, dairy products like milk, cheese, yogurt, and butter should be avoided in your compost bin. They share the same drawbacks:

• Pest attraction: Dairy products are a magnet for unwanted critters.
• Foul odors: Anaerobic decomposition of dairy leads to unpleasant smells.
• Potential pathogens: Dairy can also harbor bacteria that may not be completely eliminated during composting.

Exception: Again, hot composting *couldpotentially break down small amounts of dairy. However, the risks generally outweigh the benefits, especially for beginners. It's best to keep dairy out of your compost altogether.

3. Oils, Fats, and Grease

Cooking oils, fats, grease, and oily foods (like salad dressings or mayonnaise) are detrimental to your compost pile. They:

• Impede airflow: Oils and fats can coat compost materials, reducing airflow and slowing down decomposition.
• Attract pests: These substances are incredibly appealing to rodents and insects.
• Create unpleasant odors: Rancid oils and fats produce foul smells.

Pro Tip: Dispose of cooking oils and grease properly by collecting them in a sealed container and taking them to a recycling center or designated disposal facility. Never pour them down the drain, as they can clog your pipes and harm the environment.

4. Bones

Bones, whether from meat, poultry, or fish, are incredibly slow to decompose and should not be placed in your compost bin. They:

• Take a very long time to break down: Bones can remain intact for years, even in a well-managed compost pile.
• Attract pests: Though they may not smell as strongly as meat, bones can still attract rodents and other animals.

Alternative: You can potentially break down bones for use as fertilizer through a process called bone charring, but this requires specialized equipment and knowledge and is not suited for home composting.

5. Pet Waste

Dog and cat feces, as well as kitty litter, are definite no-nos in your compost pile. They:

• Contain harmful pathogens: Pet waste can harbor parasites, bacteria, and viruses that are dangerous to humans and can contaminate your garden soil.
• May not break down completely: Some components of pet waste, like kitty litter, are not biodegradable.

Important Note: Even if you have a hot composting system, it may not reach temperatures high enough to kill all the pathogens in pet waste. It's simply not worth the risk. Dispose of pet waste properly in the trash.

6. Diseased Plants

Avoid composting plants that are infected with diseases or infested with pests. These problems can:

• Spread diseases and pests: Composting diseased plants can reintroduce pathogens and pests into your garden when you use the compost.
• Contaminate your compost pile: The entire batch of compost can become infected, making it unsuitable for use.

Safe Practices: If you suspect a plant is diseased, it's best to burn it (where permitted), bag it and dispose of it in the trash, or bury it deeply in a location far from your garden. Do not compost it unless you are absolutely certain your composting method will kill all pathogens.

7. Chemically Treated Yard Waste

Grass clippings, leaves, and other yard waste that have been treated with herbicides, pesticides, or other chemicals should not be composted. These chemicals can:

• Harm beneficial microorganisms: Chemicals can kill the good bacteria and fungi that are essential for composting.
• Contaminate your compost: The chemicals can leach into your compost and harm your plants when you use it.

Considerations: Be mindful of where your yard waste comes from. Avoid composting materials from lawns or gardens that are regularly treated with chemicals. If you are unsure, it's best to err on the side of caution and dispose of the materials in the trash.

8. Walnut Tree Leaves and Twigs

Black walnut trees produce a substance called juglone, which is toxic to many plants, including tomatoes, peppers, and eggplants. Avoid composting:

• Spreading Juglone: Composting walnut leaves and twigs can spread juglone to your garden.
• Plant growth inhibition: Juglone can inhibit or kill sensitive plants.

Best Practice: Even hot composting may not completely break down juglone. Dispose of walnut leaves and twigs separately.

9. Coal and Ash

Avoid adding coal ash to your compost, as it can contain:

• High levels of sulfur and other heavy metals: These can be harmful to plants and soil.
• Alter Soil pH: Coal ash can significantly alter soil pH.

Wood ash: Wood ash, in moderation, can be beneficial for compost, adding potassium and raising the pH. However, use it sparingly as too much can create alkaline conditions.

10. Invasive Plants

Invasive plants like bindweed, Japanese knotweed, and ivy are aggressive growers that can take over your garden. Composting them can lead to:

• Spread Through Compost: Seeds and roots can survive the composting process and sprout in your garden.
• Difficult Eradication: Once established, invasive plants are difficult to get rid of.

Recommendations:: Dispose of invasive plants by burning them (where permitted), drying them thoroughly in the sun before disposal, or bagging them securely and throwing them in the trash.

11. Plastic, Glass, and Metal

These materials are not biodegradable and will not break down in your compost pile. They can also:

• Physical Contaminates: Contaminate your compost and make it unsuitable for use.
• Potential Harm: Present a hazard to anyone handling the compost.

Sorting and Recycling: Always sort your waste carefully and recycle plastic, glass, and metal whenever possible.

12. Glossy or Coated Paper

Glossy magazines, coated paper, and some types of cardboard may contain inks and coatings that are harmful to your compost. They can:

• Introduce Chemicals: Release harmful chemicals into your compost.
• Slow Decomposition: Take a long time to break down.

Suitable Alternatives: Stick to plain paper, newspaper, and uncoated cardboard for your compost pile.

13. Treated Wood

Treated wood, such as lumber used for decks or fences, is often impregnated with chemicals to prevent rot and insect damage. These chemicals are harmful and can:

• Contaminate Compost: Leach into your compost and harm your plants.
• Environmental Hazard: Pose an environmental hazard.

Untreated Wood: Untreated wood can be composted, but it will break down very slowly. Smaller pieces will decompose more quickly.

14. Tea Bags (Some Varieties)

While tea leaves are excellent for compost, many tea bags contain plastic or nylon fibers that do not break down. Make sure to:

• Check The Material: Ensure your tea bags are made of paper or biodegradable materials.
• Remove The Bag: If in doubt, remove the tea leaves from the bag and compost them separately.

15. Dryer Lint (Synthetic Fabrics)

Dryer lint from natural fibers like cotton and wool can be composted. However, lint from synthetic fabrics like polyester and nylon contains microplastics that can:

• Pollute Soil: Contaminate your compost and soil with microplastics.
• Environmental Concerns: Pose an environmental hazard.

What CAN You Compost? A Quick Reminder

Now that you know what not to put in your compost bin, let's quickly recap the items that you *cancompost safely and effectively:

• Fruit and vegetable scraps: Peels, cores, stems, and other unwanted parts of fruits and vegetables.
• Coffee grounds and tea leaves: These are excellent sources of nitrogen.
• Eggshells: Crush them for faster decomposition and to add calcium to your compost.
• Yard waste: Grass clippings, leaves, twigs, and small branches (shredded).
• Paper and cardboard: Plain paper, newspaper, and uncoated cardboard (shredded).
• Sawdust and wood shavings: Untreated wood only.

Tips for Successful Composting

Beyond knowing what to avoid, here are some additional tips for creating healthy and thriving compost:

• Maintain a good balance of greens and browns: Greens are nitrogen-rich materials like food scraps and grass clippings, while browns are carbon-rich materials like leaves and paper. A good balance is roughly 1:1 or 2:1 browns to greens.
• Chop materials into smaller pieces: This will speed up the decomposition process.
• Turn your compost regularly: Turning provides oxygen to the microorganisms and helps to distribute moisture.
• Keep your compost moist: The compost should be damp like a wrung-out sponge.
• Monitor the temperature: A hot compost pile (130-160°F) will decompose materials more quickly and kill more pathogens.
• Be patient: Composting takes time. Depending on your method and the materials you use, it can take anywhere from a few weeks to several months to produce finished compost.

Troubleshooting Common Composting Problems

Even with the best intentions, composting can sometimes present challenges. Here are some common problems and how to address them:

• Smelly compost: This usually indicates anaerobic decomposition. Turn the pile to introduce oxygen and add more browns to balance the moisture and nitrogen levels.
• Slow decomposition: Make sure you have a good balance of greens and browns, and that the compost is moist enough. Turn the pile regularly and chop materials into smaller pieces.
• Pests: Avoid composting meat, dairy, and oily foods. Secure your compost bin to prevent access by rodents and other animals.
• Compost is too wet: Add more browns to absorb excess moisture and turn the pile to improve airflow.
• Compost is too dry: Add water to moisten the pile and turn it to distribute moisture.

Conclusion: Compost with Confidence

Composting is a rewarding and sustainable practice that can benefit your garden and the environment. By understanding what not to put in compost, you can avoid common problems and create nutrient-rich compost that will nourish your plants for years to come. So, get started today and turn your waste into garden gold!