Organics: What is Compostable?
Updated: Sep 14
There are many different ways to compost, and it can be as simple as a pile in the backyard or a pickup service. However, there are a few things you can do to ensure you are composting properly. Composting matters, and this blog will guide you.
Organic waste is a large category, but it includes anything that comes from living organisms, like plants or animals. Some common types of organic waste include yard waste, food waste, and compostable packaging or products. Most of these can be composted, but not all of them, and not all in the same way.
Compost is the process by which organic material breaks down into dirt; nature’s version of recycling.
Composting is an important part of the circular economy, and is part of what is called the nutrient cycle. The nutrient cycle is the process by which nutrients in organic matter are broken down and returned to the soil. A great metaphor for the nutrient cycle is a forest. In the spring, the trees use sunlight, water, and nutrients in the soil to grow leaves. In the fall, those leaves drop to the ground where they compost and turn back into soil that will be used to grow new leaves again. Nothing is wasted in the system—it is reused again and again.
What Types of Organic Waste are Compostable?
It’s important to know which type of composting you are doing in order to know whether something is compostable. Backyard composting, indoor composting, bokashi composting, vermicomposting, and curbside pickup services all have different requirements on what is and isn’t compostable. If you are using a compost drop-off or pickup service, make sure to check with your composting provider to see what items they accept for composting.
What is included in yard waste?
Pretty much every type of plant matter in your backyard is considered yard waste. This can include lawn clippings, leaves, flowers, plants, small sticks, branches, and even soil.
Is yard waste compostable?
Yes! Yard waste can be composted right in your backyard. For example, grass clippings can be mulched and left to decompose right on the lawn. Some communities also pickup yard waste and compost it at a commercial yard waste facility.
Watch out for:
Large branches or logs: Because of their large size, logs and large branches take a long time to break down. These should be taken to a commercial composting facility or disposed of in the trash.
Treated wood or mulch: Treated wood and colored mulches contain chemicals that contaminate compost. These must be disposed of in the trash.
Diseased plants or invasive species: Composting plants with fungus, disease, or insect-infestations can contaminate any soil coming out of your compost. Invasive species can regrow from compost and should be thrown away instead.
There are two main kinds of food waste—wasted food and food scraps. Wasted food is any food that could be eaten, but is instead thrown away. This includes food that goes bad and must be thrown out. Food scraps include the parts of food that are technically edible, but not very appetizing. This includes items like banana peels, carrot tops, or apple cores.
Fruits and Vegetables
This includes any kind of fruit or vegetable and any food scraps, like seeds or stems.
Are fruits and vegetables compostable?
Fruits and vegetables are especially easy to compost, and be composted by pretty much any method of composting.
Watch out for:
Citrus fruits: While these are compostable in small amounts, too many in your compost pile can increase the acidity, which harms the bacteria necessary to compost. Make sure to balance these out with other kinds of less acidic fruits and vegetables.
Grocery stickers: These are a common contaminant in compost and should be removed before composting
Meat and Dairy
This includes any animal products like milk, cheese, eggs, seafood, or meat and food scraps like bones, skin, or scales.
Are meat and dairy compostable?
Technically, yes. However, these items may not be suitable for backyard composting because they can produce foul odors and attract pests. If you have a composting pick-up service, check to see what kinds of meat and diary they accept, if any. Note that eggs and egg shells, both raw and cooked, are compostable, and actually provide critical nutrients to the soil.
Watch out for:
Bones: Most bones are not compostable and must be thrown in the trash.
Bacon and other kinds of grease: In addition to attracting pests, grease and oils can harm the water balance of compost piles, and should be thrown in the trash.
Seafood shells and peels: Although technically compostable, these tend to smell and can attract pests, so they should be thrown away instead.
This includes most food that has been baked, cooked, or prepared by either an individual or commercial facility.
Are prepared foods compostable?
Most prepared foods are compostable, however, it is important to remove any parts that are not compostable.
Watch out for:
Meat and dairy: In many cases, foods containing large amounts of meat or dairy should be left out of your compost. Small amounts of meat or dairy are fine, such as the butter in muffins or soups made with chicken broth.
Foods high in oil or grease: These should be thrown out rather than composted. For example, this can include foods that are deep-fried or cooked in oils.
Foods high in sugar: Sugary foods and beverages are safe to compost, but should be limited to small amounts. Too much sugar can upset the balance of the compost and even cause fermentation.
Types of compostable packaging
This includes packaging that is certified compostable, like compostable bags or packaging made from plants, like sugarcane or bamboo.
Is compostable packaging recyclable?
While these are technically compostable, many of these are only compostable in industrial settings—not in backyard composting. Some varieties of compostable packaging may also contain PFAS or toxic, persistent chemicals and should be thrown away. If using a compost pickup or drop-off service, check to see which kinds of compostable packaging they accept, if any. Indiana does not have many commercial composting facilities, making it difficult to compost these in most places throughout the state.
What kinds of paper are compostable?
Most low-quality paper products can safely be composted. This includes paper towels, napkins, paper egg cartons, brown packing paper, and molded fiber inserts, such as the cardboard that comes inside shoes.
Watch Out For:
Plastic Stickers: The stickers on paper egg cartons or fiber inserts should be removed before composting.
Paper towels used with chemicals: Chemicals can contaminate compost, so paper towels used with chemicals should be thrown in the trash.
Paper with heavy inks or coloring: Ink can contain heavy metals that can contaminate compost and should be recycled instead. Paper recycling facilities can remove and safely manage the inks on paper.
Thank you for Composting
Now that you know the basics of organics and composting, we encourage you to share that knowledge with your circles of influence, like your family, friends and neighbors! To learn more about organics and food waste management, check out our organics page or our webinar on food waste. Thank you for composting!
Save the graphics below for easy reference on what is compostable:
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