Composting is a very simple process that nature takes to break down organic materials into a natural fertilizer for use in the home garden and yard. But one item people often ask is, what items can be composted? This will be a guide for what list of materials you can use to determine if you can add it to your compost pile or bin.
If you are reading this, I assume you already have a good idea of what compost is, and how to get started making a basic compost pile. This article will cover the finer points of specific materials, starting from a high level as to how your temperature and other conditions can effect what should/shouldn’t be composted. By the end of the article you should have a full understanding of what materials you can add to a compost pile.
If you are in a rush, then you can simply download a printable list of items to compost. But I would urge you to return though and review some of the other points we make in this article as it relates to the importance of temperature and other factors to consider.
How this article is organized:
- How temperature effects what should/shouldn’t be composted
- What materials shouldn’t be composted
- Basics of Compost, what ingredients are needed
- Kitchen Materials that can be composted
- Yard Materials that can be composted
- Household items that can be composted
- Pet items that can be composted
How temperature effects what should be composted
This may seem like a silly topic for a list of materials that should be composted, but it isn’t. If you are expecting to make compost in 4-8 weeks, then you need a pile to get hot. High temperature accelerates the decomposition of organic material. And certain plant materials may take up to a year to decompose under cold or ambient temperatures. So, getting your pile hot is very beneficial.  
To make sure you get a hot pile, you will need to achieve a large volume of material. A good rule of thumb is to make your pile 3-4′ diameter (1-1.3m) and it will be sufficiently large to get hot. For a more detailed explanation, read our guide on making a hot compost pile.
Plant materials that are difficult to compost
Everything will compost given enough time. But there are certain plants that have thick, tough leaves that can take a year or more to break down under regular ambient conditions. To help accelerate their decomposition, you should shred them with a lawnmower and make sure you have a hot compost pile:
- Palm fronds
- Live Oak leaves
- Holly leaves
- Southern Magnolia leaves
- Mountain Laurel leaves
- Rhododendron leaves
High temperatures kill weed seeds
Another reason we need to understand what temperatures our pile will reach is because of seeds. A hot pile that reaches 120F for about 7 days, or 140F for several days will kill/sterilize any weed seeds that may be in grass trimmings or yard waste.  The higher temperatures weaken a seeds natural defenses at decomposition, as well as accelerate it.
If your pile or bin isn’t large enough to get hot, you may not be able to kill the seeds from common yard weeds such as dandelion, sorrel, or clover. If that is the case, you should not add these materials to the compost pile. If your finished compost contains weed seeds, you may just end up spreading weed seeds all over garden or yard!
High temperatures will kill diseases on plants
An old garden adage states to never compost diseased plant material. And if your pile is ‘cold’ or not hot, then this can be a good policy. But a hot compost pile will kill all plant diseases via the high temperatures.
What materials should not be composted
In general, any plant material can be added to a compost pile hot or cold, and given enough time will decompose. But you should avoid using plant materials for composting if they have been treated with pesticides or herbicides. Grass clippings or yard waste that has come in contact with pesticides should not be added to a compost pile.
You may be asking yourself, I don’t use herbicides on my grass, but what about the previous owner? Well, that vast majority of lawn chemicals and herbicides will break down organically, given enough time. The trick is figuring out how long that will take. Some herbicides have a half-life of a month or two, while others such as glyphosate has a half-life of 18 months to 3 years.
Each half-life will reduce the amount of herbicide present by 50%. For example, you need about 5 half-lives to reduce the original amount of herbicide by 93%. So, you need to figure out what the herbicide was, what it’s half-life is, and then multiply that amount of time to reduce it. But, know that these half-lives are under certain conditions. And those conditions are probably different from your own yard. Thus, any attempt to determine this is going to be somewhat of an educated guess.
Meat, dairy, and oils should not be composted
As a general rule, you should not compost any meat, dairy, or oily cooked foods. These materials can often attract rodents or animals to your compost pile. Also, oils tend to saturate but no evaporate, and can squeeze out air leading to areas of anaerobic bacteria (cold compost bacteria that is very slow to decompose things).
Now, if you have a very large and hot pile, you can compost almost any material, even meat and cheese. The high temperatures will dissuade animals and help accelerate the breakdown. But this is easily achievable for large commercial compost facilities. It is difficult for a backyard composter to make a large enough pile to do this, and having such a large pile can also lead to risks of the compost pile catching on fire.
Furthermore, if you compost meats and the temperature is not very high, you will likely have fly larvae and maggots in your pile (personal experience!). So, in general, stick to plants.
Never compost dog or cat feces
Dog and cat feces should not be composted as they can contain parasites that can survive high temperatures of a compost pile. These parasites are harmful to humans, and if they were transferred to your vegetables you could unwittingly ingest them. So, best to dispose of the pet feces in the trash.
Be cautious with paper and cardboard products
While many sources say it’s fine to compost news paper or cardboard (even cereal boxes), I would recommend you not do so. The reasoning for this is that glossy finishes and colored inks can contain heavy metals that may contaminate your garden. Now, it will take many years of heavy use to do so, but if you can spend a reasonable effort to avoid the risk, you should do so.
If you want to learn all the nitty gritty details of what can be in colored or glossy paper/cardboard products, you can read about it here.
Basics of Compost, what ingredients are needed.
Four main ingredient categories are needed to make compost.
- Green materials – fresh ingredients that are rich in nitrogen
- Brown materials – dried plant or paper based products that are high in carbon
- Water – An active compost pile needs to be moist, but not wet to function and decompose properly. You need to maintain
- Air – active compost piles need oxygen to function
Water and air need no further explanation. But for people new to composting, what kind of materials should they gather can be confusing. From a high level, the most common items that are used to make a home compost pile are the following:
|Common Green materials for compost||Common Brown Materials for compost|
The above materials are easy to accumulate for most homeowners. A good rule of thumb is your overall pile should be around 50/50 green to brown material by volume, and a total size of 3′ diameter and tall. This helps ensure your compost pile will heat up to accelerate the decomposition, assuming other best practices are followed such as maintaining proper moisture levels as well as frequent turning.
But, what constitutes a green or a brown material, and if it is safe to compost is another matter. Below you will find a list of green and brown materials that you can compost, based on the household source.
Note – you can download & print our complete printable list of items to compost here.
List of kitchen items that can be composted
|Number||Kitchen Material||Green / Brown||Special instruction|
|3||Egg shells||Green||Crush them up|
|5||Corn cobs & husks||Green|
|7||Citrus rinds/peelings (orange, lemon, lime)||Green||These are fine in a compost pile, but not ok for a worm bin / vermicomposting.|
|10||Squash skins / cores||Green|
|14||Expired canned vegetables||Green|
|19||Rotten tomato sauce or paste||Green|
|20||Expired spices / herbs||Green|
|21||Expired granola/protein bars||Green|
|22||Avocado pits||Green||Often germinates in compost piles / slow to break down|
|23||Peach pits||Green||Slow to break down|
|24||Spoiled cheese||Green||Use in moderation, deep inside pile|
|30||Crayfish / Crawdad shells||Green|
|32||Pizza box||Brown||Only non-greasey parts without colored ink|
|33||Paper towel cardboard rolls||Brown||Shredded|
|34||Paper towels / napkins||Brown||Shredded|
|35||Brown Paper bags||Brown||Shredded|
|37||Chopsticks||Brown||Only plain wooded chopsticks should be composted|
|39||Paper plates||Brown||Only white or brown, uncoated|
|40||Egg cartons||Brown||Only those made from recycled paper/cardboard. Shredded|
|41||Egg shells (crush them up)||Brown|
|44||Stale chips, tortillas, pitas||Brown||Only plain wooden chopsticks should be composted|
|47||Stale nuts / peanuts||Brown|
|48||Nut shells (walnut, pistachio, etc)||Brown|
|50||Sunflower seed shells||Brown|
|51||Popcorn kernels||Brown||Can be cooked or uncooked|
|52||Wine corks||Brown||Chopped up|
List of yard items that can be composted
|Number||Yard Material||Green / Brown||Special instruction|
|53||Grass clippings||Green||Must be well mixed|
|55||Fresh leaves||Green||Torn or cut up|
|56||Weeds||Green||Safe if you have a hot pile. If not, remove seed heads.|
|57||Seaweed||Green||Torn or cut up|
|58||Excess fertilizer||Green||Nitrogen rich fertilizer (no pesticides/herbicides)|
|60||Cut flower arrangements||Green|
|61||Urine||Green||Urine is rich in nitrogen. It is an excellent green material.|
|62||Pumpkins / Jack-O-Lanterns||Green||Gather these in November to make a hot Winter compost pile|
|63||Used potting soil||Brown|
|64||Flowerbed or garden fall clean up stalks||Brown|
|65||Dead flower stalks||Brown|
|69||Dust from sweeping floor or dust bunnies||Brown|
List of general household items for composting
|Number||Household Items||Green / Brown||Special instruction|
|71||Brown packing paper (kraft paper)||Brown||Shredded|
|72||Shredded cardboard||Brown||Torn or shredded|
|73||Shredded paper||Brown||No colored paper or inks|
|74||Toilet paper rolls||Brown||Used or clean, both can be composted|
|75||Kleenex / tissues||Brown||null|
|76||Envelopes / junk mail||Brown||Non-glossy white paper plain or with black ink only|
|77||Straw||Brown||People often discard after Autumn|
|78||Sawdust||Brown||From untreated, plain air-dried or kiln dried wood|
|79||Hair from brushes||Brown||null|
|80||Hair clippings / beard trimmings||Brown||null|
|81||Finger nail clippings||Brown||null|
|82||Lint from natural fabrics||Brown||null|
|83||Cotton balls||Brown||100% Cotton only|
|84||White cotton clothes||Brown||100% Cotton only|
|85||Wool clothes||Brown||100% Wool only, shredded|
|86||White cotton sheets||Brown||100% Cotton only|
List of pet items that can be composted
|Number||Pet materials||Green / Brown||Special instruction|
|89||Horse Manure||Green||Need to hot compost, as it can contain weed seeds|
|91||Guinea pig manure||Green|
|92||Manure from herbivoires||Green|
|93||Deer manure||Green||Often can be found in yard|
|94||Chicken manure||Green||Warning – must reach 140F for 7 days or sit for a year before use! Salmonella / Pathogen risk|
|95||Old pet food||Green|
|98||Spoiled pet food||Brown|
|99||Wood shavings from horse bedding||Brown|
|101||Rabbit/Guinea Pig bedding||Brown|
Composting is really a way of life. Once you realize how many different things found around your house can be composted, you will start doing so, and feel great about it. You will be amazed at just how much landfill space could be saved if more people composted at home.
 – Bob Bergland, US Secretary of Agriculture et al. “REPORT AND RECOMMENDATIONS ON ORGANIC FARMING. USDA Study Team on Organic Farming“, United States Department of Agriculture, July 1980
 – Graves, R. E., and G. M. Hattemer. “Chapter 2 Composting. Part 637 Environmental Engineering National Engineering Handbook. United States Department of Agriculture.” Natural Resources Conservation Service (2000).
 – Soil Building – Manures & Composts. United Stated Department of Agriculture. Accessed 01JUL2022.
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