List of Foods That Can Be Composted

Any materials that used to be a plant can go into your compost bin, including all fruit and vegetable scraps. These materials serve as "greens" in compost lingo: moist, fresh materials rich in nitrogen that you should add at roughly half the volume of dried "brown" ingredients such as leaves and cardboard. (See References 2) If you're composting with worms --- a technique called vermicomposting --- then you need to exercise a bit more care when adding fruit scraps to your worm bin. Limonene, a compound found in citrus, is toxic to worms, so you should only add citrus fruits in small quantities to worm bins, or none at all. (See References 3) For best results, when adding scraps from fruits and vegetables, chop or break them into smaller pieces. This will speed up the deterioration by providing more surface area for microorganisms to feed on. Don't get carried away, though, by mincing your compost additions too small. Tiny particles can prevent proper oxygenation in the pile and slow the breakdown process. (See References 4)

You should avoid adding most animal-based food products to your compost, including meat, bones, dairy items and oil or grease. These foods create odors and attract pests and scavengers to your compost heap. However, eggshells are one animal-based product you should add. (See References 2) Although low in the primary plant nutrients, eggshells contain high levels of calcium, which plants need for a strong structure, and other trace minerals (See References 5, page 234, and References 6).

Tea and coffee come from plant sources, so you can add tea leaves and coffee grounds to your compost bin, too. As a source of nitrogen, they are considered "green" ingredients in your compost. Paper acts as a carbon-rich "brown" ingredient, so throw in shredded teabags and coffee filters as well. (See References 2)