Composting is a hot (bin) topic here at SJ and one of the most life-changing sustainability practices we’ve adopted. However, it’s not been without a certain amount of trial and error, including learning about what is compostable and what’s not.

Maybe you’re experimenting with apartment composting or have a compost bin on the patio. You might be going old school with a simple compost pile in the backyard. Whatever your composting method is, you’re on your way to making one of the biggest positive impacts on the environment (read: reduce an extremely potent greenhouse gas).

High five to that!

What Is Considered Compostable?

So, how do you know what’s compostable and what not to compost?

Let’s first define “compostable”: Anything that can completely break down into natural elements without leaving toxic residue in a relatively short period of time. (The time element is crucial when talking about things that are biodegradable vs compostable.)

For example, a garment made of 100% organic cotton is considered compostable because it will break down back into carbon and humus (the finished product of the process we call compost). Whereas something made of synthetic fabrics would merely break apart into smaller microplastics (leaving toxic residue behind) over the course of many years.

Compostable waste falls into one of two categories. Both are necessary for a successful compost pile and perform best when alternated in thin layers.

  • Green: Nitrogen-rich materials like grass clippings, spent coffee grounds, and fruit and vegetable scraps. These wet materials help maintain moisture and rot down quickly.
  • Brown: Carbon-rich materials like paper, cardboard, prunings, dead plant matter, and other yard scraps. These provide aeration and structure, but because they break down slowly, it’s best to chop/tear them into small pieces.

We’ve broken down (pun intended) our list of compostable items into sections based on where you might find them in your home. We’ve also split them into brown and green organic matter, so you know you’re getting the right balance for your composting process.

It’s worth noting that while this list is designed for those wanting to compost at home (indoor compost bins included), industrial compost facilities can compost a lot more (e.g., dairy, meat, and bones). More and more councils/municipalities are starting to offer food/composting collection services, so check out what’s available in your neighborhood for things not included on this list.

Now let’s get rot down to it (or watch our video explainer below for the highlights).

Contents: What To Compost

  1. What Is Compostable In The Kitchen? Jump to section
  2. What’s Compostable In The Garden? Jump to section
  3. Things That Are Compostable In The Bathroom Jump to section
  4. What Can Go In Compost From The Office? Jump to section
  5. What Is Compostable Waste From Pets And Animals? Jump to section
  6. Compostable Items From The Holidays Jump to section
  7. Other Compostable Materials Jump to section

What Is Compostable In The Kitchen?

Between filling it with eco-friendly cookware and repurposing your vegetable scraps, the kitchen is the place to support our planet. But even though it’s all technically organic, not all food should go in your home compost.

Composting Cooked Food, Meat, Fish, and Dairy

Grease, most animal products, and food packaging should be left out of the compost bin.

Composting cooked food should also generally be avoided unless you have a set-up specifically designed to handle it. Adding cooked food to a traditional compost pile or bin risks several problems:

  • It attracts pests. Mice, rats, flies, foxes, (bears?!) will be attracted to cooked food.
  • It can negatively affect the composting process. Cooked food is wet and soggy, affecting the moisture levels and aeration of your compost environment.
  • It smells bad!

Small amounts of cooked vegetables (cooked without oil) may be okay in a well-balanced compost set-up that reaches high enough temperatures. To play it safe, it’s a good idea to invest in a specialized bin for cooked food and animal products like a Green Johanna, bokashi bin, or Green Cone.

The Green Johanna is a type of hot composting bin that can deal with all of your cooked and raw food scraps, meat, fish, and dairy, included.

A bokashi bin ferments food waste in a sealed anaerobic environment using a special inoculated bran to expedite the composting process. You can go ahead and compost everything in this one, including bones. Just be aware that while the bokashi process makes the bones safe to add to your garden soil, they won’t be broken down (and you’ll find yourself digging up bones months/years later!).

Not technically a composter, but rather a “food waste digester,” a Green Cone is a solar-powered solution to dealing with cooked food and animal products. It doesn’t produce compost, but the underground basket releases nutrients into the soil and nourishes nearby plants.

Let’s assume, though, that you have a standard indoor bin or outdoor compost pile in your backyard. In this case, the following kitchen materials and food are compostable at home.

Kitchen Composting Green Materials

1. Fruit and vegetable scraps: Think potato skins (though these can also be eaten!), leftovers from juicing, broccoli stalks, apple cores, soggy lettuce, seaweed, and moldy peppers, to name a few.

2. Corn husks and chopped-up cobs

3. Non-acidic fruit peels: Banana peels, avocado skins, and melon rinds are okay, but avoid too many grapefruit, orange, lime, and lemon peels. Citrus fruits can make your compost overly acidic and can kill your worms.

4. Fruit pits: Soak in boiling water and blend to speed up the decomposition process.

5. Fruit seeds: Chopped up to prevent sprouting in your compost (unless you want that).

6. Spoiled plant milk: Sustainable milk alternatives like almond, soy, oat, and coconut—but NOT dairy milk, which will produce a rotten stench and attract pests.

7. Moldy cheese: Only in very small amounts and buried in your pile.

8. Beans and other legumes

9. Herbs and spices

10. Tea leaves and natural paper tea bags: Be careful, though, as most have plastic in them—it’s best to choose loose-leaf tea from zero waste tea companies.

11. Coffee grounds

12. Liquid filling from canned fruits and vegetables

13. Expired jams and other preserved food

14. Symbiotic culture of bacteria and yeast (SCOBY): If you accidentally kill your SCOBY or just breed too many while brewing and flavoring kombucha at home, toss that gelatinous blog in the compost.

15. Soured organic beer, liquor, and wine. Even soil has a palette!

16. Old condiments: Things like moldy pasta sauce, ketchup, relish, soy sauce, mustard, and the like are okay, but only in small amounts as they can be acidic.

17. Tofu

Kitchen Composting Brown Materials

19. Stale bread, tortilla shells, and leftover pizza crust: Buried in the pile so they don’t attract pests.

19. Stale cereal, oatmeal, and granola bars

20. Stale crackers, cookies, pretzels, and chips

21. Dry rice and pasta: Cooked rice and pasta are also compostable, but try not to overdo it as the excess moisture may make odor management tricky. Cooked rice also breeds bad bacteria.

22. Crumbs

23. Grape and other fruit stems

24. Nutshells: Be warned: these will take longer than the other items here to break down. Leave out walnut shells, as they contain juglone, which is toxic to some plants.

25. Popcorn: Leftover, unpopped, or burnt

26. Eggshells: Rinsed (to deter pests) and crushed to speed up decomposition.

27. Cardboard egg cartons

28. Unbleached coffee filters

29. Real wine corks: Chopped into relatively small bits

30. Brown paper shopping bags

31. Paper lunch sacks

32. Cardboard food boxes

33. Used paper napkins and paper towels (paper towels are not recyclable just FYI).

34. Non-grease-soaked paper towels: Read up on the specifics of composting paper towels, and don’t forget to shred the cardboard center roll.

35. Corrugated cardboard pizza boxes: Only parts that aren’t saturated with grease.

36. Parchment paper: Unbleached and unwaxed

37. Cupcake and muffin paper wrappers without waxy linings

38. Non-coated paper plates: They can have some food stains but should not be saturated in grease.

39. Paper cups without a waxy or plastic lining: No Dixie Cups, for instance.

40. Wooden chopsticks and bamboo skewers

What’s Compostable In The Garden?

Plenty of yard waste can be composted. Just be sure to look out for weed seeds, diseased plants, and anything else that can spread through the compost. Also, know that things like woody prunings can take a long time to decompose, especially if not chipped into tiny pieces.

Lawn / Garden Nitrogen Rich Material

41. Green leaves

42. Grass clippings: While an excellent compost ingredient, cut grass can become compact, forming a dense air-tight clump, making the breakdown process anaerobic. Make sure to thoroughly mix grass trimmings with the rest of your compost material or spread it thinly on top.

43. Sod chunks

44. Deadheaded flowers

45. Weeds: Avoid weed seeds as these can spread via compost and cocause a garden disaster!

46. Spent bulbs

47. Thinned-out, weaker plants (including indoor plants)

Lawn / Garden Carbon Rich Material

48. Non-coated, paper seed pouches

49. Dead leaves

50. Dead plants (including their roots and soil): Be sure to determine their cause of death, because plant diseases and plant infestations can spread.

51. Bush and shrub trimmings

52. Hay, straw, or alfalfa (make sure that these haven’t been treated with herbicides).

53. Sticks and twigs: Break these into small pieces. They will already take a long time and need a lot of nitrogen (to balance out their high carbon content) to break down.

54. Sawdust and wood chips (from untreated wood only): As with grass, beware of clumping. Be sure to either layer between other materials or lightly sprinkle them on.

55. Pine needles and pine cones

56. Burned wood ashes: A great alkaline substance to balance the pH of your pile if you’ve been adding a lot of acidic items (i.e., pine needles, oak leaves, citrus fruit). These shouldn’t be confused with coal ashes, are a composting no-no due to toxic chemicals and metals.

57. Peat pots and non-plastic, home compostable seed trays

58. Coir flower basket liners

59. Leftover or outdated potting soil

60. Fallen bird nests: Please note that abandoned bird nests should be left alone, as they are sometimes reused).

61. Cut-up burlap sacks after use as pot or garden bed liners

Things That Are Compostable In The Bathroom

The bathroom is another good source of compostable materials. You may have even heard that period blood is an excellent nitrogen-rich fertilizer. If the thought of dumping out your menstrual cup in the garden gives you the heebie-jeebies, you can still source other materials from the loo.

Bathroom Composting Browns

62. Bamboo toothbrushes (remove the bristles) and silk or plant-based dental floss

63. Shredded toilet paper rolls from your eco-friendly toilet paper

64. Cotton balls and cotton swabs with cardboard sticks: If they are 100% cotton wool and not blended with synthetic material. Also, make sure they don’t have synthetic makeup or skincare products on them.

65. Fingernail clippings

66. Human hair and razor trimmings

67. Cardboard packaging from personal care products

68. Used facial tissues: Avoid the ones you’ve used when you’ve been sick.

69. Cut-up loofahs: We mean real, eco-friendly loofahs, not those pink plastic poofs.

70. Old 100% cotton towels and washcloths

What Can Go In Compost From The Office?

Between plantable pencils and other eco-friendly school supplies, many of our office essentials are now designed to go back to the earth. Even if not specifically designed for biodegradability, there are many high-carbon items that can go from getting the job done to supporting healthy soil. Be aware however, that certain inks and laminated (AKA plastic) coatings render cardboard (among many other items) no longer compostable.

Office Composting Brown Materials

71. Newspaper: All paper-based composting materials are best composted when shredded or tor

72. Bills, plain junk mail, and other non-glossy paper documents and cards.

73. Subscription cards from magazines: You may not be able to compost the glossy pages of People Magazine, but don’t forget the standard subscription cards inside. They’re usually included in most widely published magazines.

74. Envelopes (with plastic address window removed)

75. Corrugated and plain cardboard boxes and mailers

76. Sticky notes

77. Pencil shavings

What Is Compostable Waste From Pets And Animals?

While the composting process, unfortunately, can’t help with an abundance of pet waste from our feline carnivores and waggy omnivores (sorry, Fido), it can turn some pet products and organic waste into soil-supporting compost.

Pet / Animal Composting Green Materials

78. Manure from non-carnivorous animals only (like horses, goats, cows, chickens, and sheep)

79. Some pet waste (bird droppings, manure from rabbits, gerbils, and hamsters)

Pet Composting Brown Materials

80. Dry eco-friendly dog food and cat food

81. Animal fur or feathers

82. Rodent pet bedding (e.g., sawdust): Again, from your herbivorous pets only.

83. Fish or rodent food pellets

84. Newspaper cage liners

85. Chewed-up bamboo, cotton or hemp eco-friendly dog toys

86. Worn-out hemp or bamboo dog collars and dog beds made from natural fibers.

Compostable Items From The Holidays

Stocking up on eco-friendly gifts isn’t the only way to be sustainable around the holidays. What you do during clean-up can be just as green. From feast-prep food scraps to the shredded paper in gift boxes, many of our holiday materials can go in the compost bin.

Holiday Composting Greens

87. Cut floral arrangements

88. Jack O’ Lanterns and decorative gourds: Channel your second favorite 90s Alt Rock band and start smashing those pumpkins before adding them to the compost pile.

Holiday Composting Browns

89. Wrapping paper that isn’t plastic coated: Try to reuse it first if you can.

90. Raffia

91. Crepe paper streamers

92. Popcorn strung around the Christmas tree (people still do that, right?)

93. Real Christmas trees: Make sure you either put it through the wood chipper or have a heyday with the hatchet first, or it will linger in a compost pile for awhile.

94. Evergreen wreaths and garlands: Remove all the wire ties and any other non-compostable metal residue first.

95. Paper tablecloths

Other Compostable Materials

Home Composting Browns

96. Stained or worn-out clothes: Clothes are compostable, but they must be made from 100% natural fabrics like cotton, linen, wool, hemp, silk, or cashmere. No synthetic fabrics, e.g., polyester, nylon, or elastane—even in the smallest blend.

97. Natural potpourri

98. Dirt and dust bunnies: Those picked up by your broom, not vacuum, which also could have picked up synthetic carpet fibers and other non-compostable materials.

99. Spent matches

100. Packaging that very clearly says “certified home compostable” on it (NOT biodegradable). We have tried some of this type of packaging with worm composting, and they don’t seem to mind. If you aren’t sure, err on the side of caution and leave it out.

101. Compostable trash bags: Again, clearly labeled as certified home compostable. They must only be filled with other compostable things from this list.

102. Unwaxed, organic string, thread, and twine

103. Non-glossy price tags