Most food scraps and yard waste break down in a home compost bin, but meat, dairy, and oils will attract pests or create odor problems
The short answer: vegetables, fruit peels, coffee grounds, leaves, grass clippings, and shredded paper all compost well. Meat, fish, cheese, butter, and cooking oil do not—they draw rats and raccoons, or they sit in the pile without breaking down. Cooked food is trickier: plain cooked vegetables and grains work, but anything with oil, sauce, or seasoning usually causes problems.
What works depends partly on your setup. A sealed bin with good airflow handles more than an open pile. A hot compost pile (one you actively manage) breaks down tougher materials faster than a cold pile you just add to over time. But even in the best conditions, some things straightforward do not belong in a home bin.
Key Takeaways
- Vegetables, fruit, coffee grounds, eggshells, leaves, and grass clippings are safe to compost and break down quickly.
- Meat, fish, dairy, oils, and fats attract rodents and should never go in a home compost bin.
- Cooked food without sauce or oil can compost, but cooked food with seasoning, butter, or sauce usually causes odor and pest problems.
- Diseased plants and weeds with seeds should not be composted unless your pile reaches 140°F or higher, which most home bins do not.
- Glossy paper, treated wood, and synthetic materials do not break down and should go in the trash.
What Breaks Down Easily in a Home Bin
Fruit and vegetable scraps are the backbone of home composting. Banana peels, apple cores, carrot tops, lettuce leaves, and squash rinds all decompose within weeks to a few months. Cut them into smaller pieces—roughly the size of a walnut—and they break down faster. Citrus peels take longer than softer scraps but still work; just do not add huge amounts at once, as they can slow the pile.
Coffee grounds and tea bags are nitrogen-rich and decompose quickly. Leave the grounds in the filter or bag, or dump them loose—both work. Avoid tea bags with plastic mesh; use only paper or cloth bags. Eggshells take months to fully break down but add calcium and do not cause problems, so include them.
Yard waste—leaves, grass clippings, small twigs, and plant trimmings—forms the bulk of many home piles. Shred or chop leaves before adding them; whole leaves mat down and slow decomposition. Grass clippings heat up a pile quickly but can smell if packed too densely, so mix them with drier materials like leaves or shredded paper.
Paper and cardboard compost if they are plain and uncoated. Shredded newspaper, plain cardboard boxes (remove tape and labels), and paper bags all work. Glossy or colored paper, magazine pages, and anything with a plastic coating do not break down and should go in the trash.
What Never Goes in a Home Compost Bin
Meat, fish, and bones are the most common mistake. They attract rats, raccoons, and other rodents, and they smell terrible as they rot. Even buried deep in the pile, they draw pests. The same rule applies to dairy products—milk, yogurt, cheese, butter, and cream. They smell, attract animals, and can introduce harmful bacteria to the pile.
Cooking oils, fats, and grease do not break down in a home bin. They coat other materials and prevent air from reaching them, which slows decomposition and creates odor. This includes butter, lard, bacon grease, and salad dressing. Even small amounts cause problems.
Diseased plants and weed seeds survive most home compost piles. A home bin rarely reaches the 140°F needed to kill pathogens and seeds. If you compost these materials, you risk spreading disease or weeds when you use the finished compost. When in doubt, throw them away.
Treated wood, sawdust from treated lumber, and synthetic materials do not belong in any compost. Treated wood contains chemicals that do not break down and will contaminate your finished compost. The same applies to plastic, rubber, and metal.
Cooked Food: When It Works and When It Does Not
Plain cooked vegetables and grains—boiled potatoes, steamed broccoli, cooked rice or pasta with no sauce—can go in a compost bin. They break down like raw scraps, though slightly slower. The key is that they have no oil, butter, or seasoning.
Anything with sauce, oil, butter, or seasoning should not be composted at home. Leftover pasta with cream sauce, roasted vegetables coated in oil, and seasoned rice all attract pests or create odor. Even a small amount of oil on a piece of chicken makes it unsuitable. When you are unsure, leave it out.
Bread, crackers, and baked goods without frosting or filling can compost, though they may attract rodents if the pile is not well-managed. Moldy bread is fine—mold is already doing part of the decomposition work. Avoid anything with chocolate, nuts, or seeds, as these can attract pests or sprout.
Materials That Slow Down or Stop Decomposition
Onions and garlic can compost but often repel worms and slow the process. Many composters skip them or add them sparingly. Avocado pits and peach pits take years to break down because of their hard shells; you can compost them, but they will still be there when you harvest finished compost.
Glossy or treated paper—magazines, junk mail, paper with colored ink—does not break down reliably. Stick to plain newspaper and uncoated cardboard. Sawdust from untreated wood works, but only in small amounts mixed with other materials; a pile of pure sawdust compacts and stops decomposing.
Charcoal and coal ash should not go in compost. Wood ash from a fireplace or wood stove can go in small amounts (it raises pH), but charcoal briquettes and coal ash contain chemicals or do not break down.
How to Know What Your Pile Can Handle
A hot compost pile—one you actively turn and manage—breaks down tougher materials faster and reaches higher temperatures, which kills some pathogens and seeds. If you turn your pile every week or two and keep it moist, you can compost more than someone with a passive pile.
A cold compost pile—one you add to over time without turning—works more slowly and stays cooler. It handles fruit, vegetables, leaves, and paper well, but struggles with anything that attracts pests or needs high heat to decompose.
If you have a sealed or enclosed bin, you can compost more than with an open pile, because rodents have a harder time getting in. Even so, avoid meat and dairy; they will still smell and attract pests trying to break through.
Start conservative: stick to fruit, vegetables, leaves, grass, and paper. Once you see what your pile does well, you can experiment with other materials. Keep a mental list of what worked and what caused problems, and adjust from there.
Frequently Asked Questions
Can I compost pizza boxes?
Yes, if the box is plain cardboard with no plastic coating or grease stains. Tear or cut the box into smaller pieces and add it to your pile. If the box is heavily greased or has a plastic lining, it will not break down and should go in the trash.
What about pet waste or cat litter?
No. Pet waste contains harmful pathogens that do not die in a home compost pile, even at high temperatures. Cat litter, even if labeled compostable, should not be used in a bin where you will grow food. Both belong in the trash.
Can I compost weeds from my garden?
Weeds without seeds can compost. If the weeds have gone to seed, do not compost them unless your pile reaches 140°F consistently—most home bins do not. When in doubt, throw them away to avoid spreading weeds in your garden next year.
Is it okay to compost a small amount of meat or fish?
No. Even a small amount of meat or fish will attract rodents and smell. The risk is not worth it. Throw meat and fish in the trash or, if your area has it, a municipal composting program that reaches high enough temperatures to handle them safely.
Can I compost glossy or colored paper?
Glossy paper and colored magazine pages do not break down reliably in a home bin. Stick to plain newspaper, plain cardboard, and uncoated paper. If you are unsure whether paper is coated, tear it—if it tears cleanly and feels rough, it is probably safe; if it tears smoothly and feels slick, leave it out.