What Can I Compost? 20 Things You Can Put In Your Backyard Compost Pile

Composting is a pretty simple concept, but it can quickly become complicated once you try sift through the available information to determine what you can and cannot add to your compost pile. It becomes even more confusing when you start reading about keeping your backyard compost bin healthy by maintaining the balance between green (nitrogen rich) and brown (carbon rich) components.

To help you get started on your composting journey and better understand what types of waste products you can put in your bin, here are 20 things you can compost. Some of them might surprise you, and you will probably notice that fruits and vegetables are not on the list. This is because most folks already know that most fruits and vegetables are fair game; therefore, the focus here is on non-produce items to add in with all those fruits and veggies.

1. Grass Clippings – If you still have a natural grass lawn, you can keep your grass clippings out of the landfill and put them to good use in your compost bin. However, you should only include them as one of your compost’s green components if you do not use chemical fertilizers, herbicides or pesticides.

2. Weeds – Some folks will tell you that you should not put weeds in your compost bin, but most backyard composters can safely include weeds as long as they have not gone to seed. If your weeds have seeds and you add them to your compost, you may end up with a lot more weeds next year after you spread that compost around your plants. If your compost pile gets hot enough, it may kill the seeds, but it just is not worth taking the chance, so make sure your weeds have not gone to seed.

3. Eggshells – Eggshells are one of the few animal products that are considered a good addition to your compost pile. Keep in mind that they take a long time to break down, which may not work well for your particular situation, but if you do not mind waiting, eggshells can add some great nutrients to your soil.

Patio Fire Pit

4. Ashes – If you have a wood-burning fireplace or a fire pit, you can save your ashes and add them to your compost. This is a great way to add much-needed carbon to your pile and a great way to keep at least some of the ashes out of the landfill. Just remember that your pile needs to stay in balance, so if you enjoy frequent nights by the fire pit or spend a lot of time entertaining guests around your patio fireplace, you will need to make sure you do not fill your bin with ashes. Make sure you leave plenty of room for green (nitrogen-rich) components as well.

5. Dry Leaves – Dry leaves are another fantastic high-carbon addition to your bin. So when you rake all of those fallen leaves as autumn rolls around, toss those leaves into your compost pile – instead of into the trash.

6. Coffee Grounds – Some people may shy away from using coffee grounds in their compost, because they likely think they are too acidic. However, most of the acid in coffee grounds is removed during the brewing process, so it is not a problem. While they are not high in acid content, they are high in nitrogen, which makes them a great addition to compost.

Coffee drinkers will have a steady supply, but if coffee is not your preferred caffeine-delivery method, check with local coffee shops to see if they give away their used grounds for folks to use in their gardens.

7. Tea Leaves and Tea Bags – Loose tea leaves are an easy addition to a backyard compost bin and can be stored with other kitchen waste in a counter top compost keeper until you have enough to justify a trip to your compost pile. Tea bags are a bit trickier, but some can be composted. Some tea bags are made with plastic or other synthetic materials, which means they are not candidates for compost, but tea bags that are made only of natural fibers are just fine. It is best to compost tea bags that are made from unbleached, natural fibers. If you are not sure if your tea bags are bleached or contain plastic, you can always just cut or rip the tea bag, compost the tea inside and discard the questionable bag.

8. Cardboard – Most cardboard products can be recycled, which is great, but it is even better if you can keep some of your cardboard out of your recycling bin and add it to your compost pile instead. It takes energy, water and transportation to recycle cardboard so, while recycling it is much better than allowing it to end up in a landfill, the better option is to use at least some of it as a brown component in your compost.

High-carbon cardboard items you likely will find around your house include toilet paper tubes, paper towel tubes, wrapping paper tubes, egg cartons and shipping boxes. Food boxes made of cardboard, such as cereal boxes, may be good for your compost bin as well, but be careful to choose those that use natural inks and do not use a plastic coating on the cardboard.

Your cardboard will break down faster if you rip it up, cut it into small pieces or run it through a paper shredder (which requires a pretty good shredder). It will also break down faster if your pile is on the wet side. You do not want your pile too wet, but cardboard will absorb excess moisture anyways, so do not be afraid to add a little water if you have added a lot of cardboard to your bin.

Also remember that high-carbon items — like cardboard — need to be balanced with high-nitrogen items, so keep that fresh kitchen waste coming if you have a lot of cardboard to compost.

9. Newspaper – Fewer families have the newspaper delivered to their homes these days, but if you are among those who still prefer the feeling of newsprint in your hands, you now have another option for discarding it afterwards. This is a carbon-rich contribution that is perfect for layering with green components (like vegetable scraps and peelings).

Tossing an entire newspaper into your compost pile is not the best idea, but if you use individual sheets for layering, rip it up or put it through a shredder, you are good to go. Just make sure you remove all of those shiny, colorful ads that are better suited for the recycle bin.

10. Junk Mail and Bills – You do not want to automatically toss all of your junk mail and old bills in your compost bin, but you can add some of it. You will need to sort out anything glossy or brightly colored, and you will need to remove the plastic address windows on envelopes that have them. Some people do not compost junk mail because it is usually not possible to know what type of ink is used, but there are plenty of backyard composters who have been shredding their junk mail and adding it to their compost for years without an issue.

11. All of Those Old Letters from Your Ex – It is probably time to finally get rid of that shoebox of old love letters hiding in the back of your closet anyways. What better way to accomplish this than to revel in running them through your paper shredder and mixing them in with the rest of the waste products in your compost bin?

12. Dead Plants and Flowers – As long as they did not die from a disease, do not have fungus and were relatively healthy before their untimely demise, you can place dead plants directly into your bin. This can also be a nice way of teaching your children about the cycle of life as they watch the dead plants decompose in your compost pile and become nutrient-rich compost to help living plants thrive.

Whenever you deadhead flowering plants that have not been sprayed with chemical pesticides, you can also toss the dead flowers in your bin.

13. Halloween Pumpkins – If you have ever carved your pumpkins a little too early, you probably already know just how quickly pumpkins can begin to decompose. While this is not good for your pocketbook when you have to buy new pumpkins to replace the rotted ones before Halloween, this quick decomposition makes them a great addition to a backyard compost bin.

14. Christmas Trees and Needles – Christmas trees can be composted, but this is a job for a die-hard composter who likes a challenge and does not mind a little extra work. A fresh pine or fir tree is not good for your compost bin, since fresh needles are too acidic, but all of those dry needles that gather on your Christmas tree skirt can be scooped up and tossed right in. Once the holiday passes and the tree dries out, you can safely add it to your bin, but you will want to chop it up or chip it for the best results.

Christmas trees do not break down quickly, so these are best for folks with large compost piles or more than one compost pile. For example, some serious composters maintain one compost bin of kitchen scraps and things that decompose quickly, and a second bin for things that decompose slower, such as eggshells or holiday trees.

15. Manure and Animal Bedding – Not all manure is appropriate for compost, but some types are absolutely fantastic. The manure that you want is from animals that eat a primarily plant-based diet, such rabbits, chickens, horses or cattle. It is best to compost manure only from domesticated animals that you are familiar with in order to avoid potential health risks, and you should never compost manure from cats, dogs or other meat-eating animals, which can pose significant health risks.

You can also compost bedding used for your rabbits, guinea pigs or chickens if you use natural bedding materials, such as straw or shavings.

Manure is a great addition to your compost, but do not go overboard. Make sure you mix it with plenty of carbon-rich components to keep your pile in balance.

16. Seaweed and Kelp – Those of us who are fortunate enough to live in coastal Southern California have access to plenty of seaweed and kelp. These prized compost bin components can be easily gathered at your nearest beach, but make sure you forage your seaweed responsibly. First of all, only take seaweed that has washed up on the shore and only take as much as you need. You will also need to make sure that you do not take sea plants from beaches that are part of a marine reserve, and check with your local authorities to see if there are regulations governing how much — if any — seaweed you can take from particular beaches.

17. Corn Cobs and Corn Husks – Most people probably assume that corn husks are on the list of things you can compost, but corn cobs are more confusing. While they may seem like bulky items that will never decompose, corn cobs will do just fine in your compost pile. Plus, you will feel a little less guilty after all of those summer backyard barbecues if you are not throwing a bunch of corn cobs in the trash.

18. Garden Waste and Trimmings – As you prune your flowering plants, thin your carrots in the vegetable garden or trim back your container garden, remember that you can place all of that garden waste and trimmings in your compost bin. For the most healthful compost, just remember to only include plant trimmings that have not been sprayed with chemical pesticides.

19. Dirt – If you have a little extra dirt lying around and are not sure what to do with it, add it to your compost bin. We have clay soil here in the San Diego area, so you do not want to go crazy with adding dirt, but if you pull up some plants that still have soil attached to the roots or have some extra dirt left over after installing some new plantings, feel free to toss it in the bin and mix it well with your other compost components.

20. Wine Corks – Wine corks made from natural cork with all packaging and labels removed can be successfully added to backyard compost piles. This is another item that will break down slower, so you might want to break it up into smaller pieces to speed things up.

Your Turn…

What are your favorite things to add to your compost bin?