Can I Compost That?

Yes, it’s not that hard.


To determine if something can be composted ask yourself

Has it once been alive?

If the answer is “yes” you can compost it.

Plants and animal derived products all fall in that category.

And now there are even composting facilities that can take care of humans, too. (Washington becomes first state to legalize human composting.)


Most reasons on lists of can and cannot compost items can be summarized by:

You shouldn’t try to compost them, because you are a novice composter or it might create problems for you because it attracts unwanted “visitors”.

With determination, knowledge and proper management you can compost all organic materials.

Compostable Materials FAQ.

A list of what you can compost at home.

Can I Compost Kitchen Waste?

Yes, you can compost most kitchen wastes. All fruit and vegetable scraps can be composted. Leftovers can also be composted. Uneaten take-out food can also be composted. Cereals, noodles and rice can also be composted. Coffee grounds can also be composted.

You can not compost kitchen wastes that are not organic compounds.

Don’t mistake organic compounds with organically grown produce.

Non-organic labeled produce are also considered organic, from a chemical point of view.

Stickers on your banana peel, metal staples on a tea bag are kitchen waste but those will not compost.

Can I Compost Yard Waste?

Yes, you can compost yard waste. To accelerate the process make sure to chop your woody materials and other larger items. You can use a wood chipper or your pruning shears. Most woody materials will be considered carbon inputs, especially once they are dried out.

Can I Compost Grass Clippings?

Yes, you can compost grass clippings. Grass and lawn clippings are considered “green” inputs, because they have a high nitrogen:carbon ratio. Grass and lawn clippings are an excellent material for your compost pile. Blend grass clippings with other materials because they are usually very dense in a heap and have poor airflow. Mixing them with carbon rich materials is a good way to increase aeration and will help with creating a warm or hot compost pile.

When composting grass clippings in your worm bin please monitor the temperature. It is an input that can increase the temperature in your compost pile. Worms like it warm but do not survive, when it is too hot. You can also manage this by leaving a large buffer zone, that does not have any clippings. This should stay colder and will give the worms a place to migrate to, when the center of your pile gets too hot.

You can buy a compost thermometer for under $20.

Can I Compost Pet Waste?

Yes, you can compost pet wastes. Afterall you cat’s or dog’s food “have once been alive.” Bird poop, turtle poop or other pet feces can be composted. Those manures are considered “green” because they have a high nitrogen:carbon ratio. Usually you can also add your pets bedding materials to the compost.

If you wish to compost your guinea pig’s, rabbit or other small pet’s waste take some precautions. When the bedding is soaked in urin it can be a bit on the agressive side for your worms. Make sure to only use the animal waste and bedding in a blend with other materials. As a guideline: Add 1/3 of your pet waste and bedding to the worm bin and keep 2/3’s with other “ingredients”. This way the worms will have a safe space to live in while they start digesting the pet waste.

This will also ensure that your compost pile won’t get too hot. Worms like it warm but can not survive high temperatures. The compost pile should stay below 105F

When using any type of manure in your compost you should follow proper guidelines to exclude pathogens from your compost. That’s primarily when you plan to use the compost in your vegetable gardens. Ideally manures are first composted with thermophilic bacteria. The increased temperatures of upwards of 130 Fahrenheit kill off pathogens and harmful bacteria. That is not mandatory, just good practice.That would be done in a separate pile and not your worm bin.

With a worm bin we are usually not reaching those temperatures, but letting the vermicast rest after it’s finished will also work.

After the initial composting phase those composts, containing animal wastes should be set to rest for a year, which will also decrease the presence of harmful bacteria. Another precaution is to not use manure based compost on a vegetable garden. It can be used to amend trees and shrubs, perennial or annual flowers, the non-edible zones of your garden.

Other manures that are great inputs for your hot compost pile are horse manure or equine bedding, cow manure, chicken manure, alpaca manure and all the other animals on your farm.

Can I Compost Citrus Fruit?

Yes, you can compost citrus fruits. Oranges, lemons and lime do break down in a compost pile. Some garden experts advise against it because they contain a small amount of oil in their peel or could lower the PH level. Although many lists tell you not to compost citrus fruits it is certainly possible to do so. Plant based oils can be composted but it takes longer and should be done in a blend with other materials to achieve balance.

When adding citrus fruits to your worm bin just make sure that you add them in a balanced way and don’t overload it with them. Make sure to add your carbon at the same time and it will be fine.

Can I Compost Milk Products?

Yes, you can compost milk, cheese and other lactose based compounds because they are also compostable. They do break down in your compostpile.

Some composting experts advise against it because those inputs attract wildlife to your compost bin. But that does not mean that you can not compost them. It means that you have to take measures to avoid attracting pests to your compost. Use a rodent-proof compost bin and create a habit of covering fresh waste with carbon rich materials to absorb the odors that attract animals.

Large amounts of milk will also alter the PH level of your compost pile and create stronger odors. That’s why we advise to add them in a balanced way and to add extra carbon at the same time.

Can I Compost Meat and Bones?

Yes, you can compost meat and bones, they do break down in your compostpile.

Any meat input to your compost can create stronger odors while they are composting. Prepare a little hole in the center of your compost material and top it off with more carbon. Alternatively you can add them on top but should top them off with a thick layer of carbon. You can test if the layer is thick enough with your nose. If you still smell it, it is not thick enough.

Some composting experts advise against composting meats because it can attract rodents to your compost bin. But that does not mean that you can not compost them. It means that you have to take measures to avoid attracting pests to your compost. Use a rodent-proof compost bin and create a habit of covering fresh waste with carbon rich materials to absorb the odors that attract animals.

Can I Compost Onions And Other Alliums?

Yes, you can compost onions. They are organic matter after all. Onions and garlic tend to lower the PH level, with that increase in acidity some microbes will have a hard time. Since those microbes are pre-digestors for everything that you feed to your worms, you want to keep them happy. The keyword is balance and the solution would be to only add a few onions, garlic or other Alliums at a time.


Can I Compost Roadkill?

Yes, you can compost roadkill.

In fact it has been a long practice to compost whole farm animals as well.

To compost dead animals you will have to make sure that you have a proper amount of carbonous materials in the mix. Those will soak up liquids and prevent odors. We would also expect the temperature of your compost pile to rise. That’s why we would advise against composting them in your worm bin.

The proper way to compost deceased animals would be in a dedicated hot compost pile. Use a compost thermometer to monitor the temperatures and check for local regulations.

For more detailed information read thisĀ  Fact Sheet of Cornell University

If you wish to compost some of the items that “can not be composted” you can take composting classes to build up your confidence and knowledge.

Or subscribe to a professional compost collection service. We recommend “Rust Belt Riders” for Clevelanders.