Composting food waste is an excellent way to reduce your environmental impact and create nutrient-rich fertilizer for your garden. However, not all food scraps can go directly into your compost pile. Understanding what can and cannot be composted is key to maintaining a healthy and productive compost system.
In this complete guide, we cover optimal composting practices for a wide variety of food items, including:
Most fruits and vegetables can be added directly to your compost pile without issue. This includes produce peels, skins, cores, stems and rotten or moldy produce. Avoid composting fruits and veggies treated with pesticides or waxes, as these can contaminate the finished compost.
Citrus peels may slow the composting process due to their high acidity. Consider chopping them finely, limiting amounts or avoiding altogether. Onion skins can mat when composting - mix them into the pile to prevent this.
Foods made from flour - like bread, crackers, cereals, chips, pastries and pancakes - compost well. Their carbon provides energy for beneficial compost microbes. Stale, moldy or burnt baked goods are perfect compost additions.
Avoid large amounts of oils or sugars, as these can attract pests. Grains like rice, quinoa and oats decompose readily - cook them first to speed up composting. Limit or avoid pasta, as it takes very long to break down.
It's best to keep dairy like milk, cheese, yogurt and butter out of your compost. Dairy turns rancid quickly, creating foul odors that attract rodents and flies. The fats and proteins also break down slowly.
If adding small dairy amounts, bury deep in the center of the pile. Never compost large quantities. Avoid eggs and meat altogether, as these decompose slowly and cause odors.
Used coffee grounds and tea leaves or bags provide excellent nitrogen for your compost. Their small size allows them to break down rapidly. Dry grounds can also help aerate and add "fluff" to wet piles.
However, large amounts of grounds can make the pH too acidic for composting. Limit to thin layers spread throughout the pile, mixing well. Remove staples from tea bags - buy compostable brands when possible.
Unbleached paper towels, napkins and plates will compost, adding carbon without chemicals. Avoid glossy or dyed paper. Cardboard egg and cereal boxes compost well when shredded - remove any stickers first.
Newspaper and cardboard break down slowly - use in moderation. Always rip or shred paper items into small pieces before adding. Avoid using bio-plastic bags or utensils labeled "compostable", as most need commercial facilities to break down.
Fruit pits, nut shells and eggshells provide important micronutrients like calcium and magnesium to finished compost. Crush or grind them first, as whole shells break down very slowly. Limit citrus peels and pineapple tops, as they take longer to decompose.
Small amounts of meat or fish bones can be composted, but break down very gradually. Bury deep in the pile to contain odors and discourage pests. For bones, a dedicated digester bin kept rodent-proof works best. Avoid pet waste, which can contain parasites.
Don't waste food scraps that have gone bad - compost them instead! Moldy, rotten or wilted produce adds valuable greens to a pile. Bury deep or mix into the center to prevent odors and animal attention.
Even spoiled dairy, meat and oils can be composted in small amounts when buried. Monitor your pile closely and add extra browns like sawdust, wood chips or dry leaves to balance extra moisture and gases. Turn the pile frequently to speed decomposition.
What food scraps should always be avoided in compost?
Avoid meat, fish, oils and large dairy amounts, as these decompose slowly and cause odors. Also keep out pet waste, fatty foods and anything treated with chemicals.
How can I speed up composting of slow items like bones or shells?
Grind or crush shells and bones before adding, and chop other items finely to increase surface area. Maintain proper moisture and oxygenation by turning piles regularly. Add extra browns like sawdust or wood chips to balance slow greens.
Is it safe to compost moldy or rotten food scraps?
Yes, decomposition is a natural process that breaks down rotting food safely. The key is to bury spoiled items deep in the hot center of the pile. Monitor for odors and add extra browns if needed. Turn frequently to speed things up.
Can I put any compostable or biodegradable item in my pile?
No - look for food-soiled paper products only. Many items labeled "compostable" need commercial composting facilities to break down. Avoid plastics and bio-bags. When in doubt, keep it out of your home compost.
Proper food waste composting relies on finding the right balance of ingredients. Follow these guidelines to enrich your soil, avoid pests and compost successfully. Monitor your pile and make adjustments to moisture, aeration and ratios as needed. With some practice, you’ll be able to compost almost all of your food scraps.