What to Compost and What Not to: A List of 100+ Items

Most food scraps can be safely composted, but there are of course some exceptions. 

For some specifics, here's a table of what food waste can be composted and what food waste you should avoid composting. We’ve also included a column to let you know if the waste is considered green or brown pre-compost. This is important to keep in mind as you need a good amount of both types, but we’ll be discussing that in more detail later.

One exception is that you don't want to compost a bunch of acidic organic waste, especially citrus peels. This will make your finished compost too acidic, which you then won't want to use in your plants.

You'll also want to steer clear of organic waste that will take far too long to compost compared to the rest of the food scraps in your compost bins. This includes waste like hard bones and fruit pits. It's also important to crush scrap like egg shells or they'll also take too long to compost.

Creating a balanced compost: get your carbon to nitrogen ratio right!

The composting process requires a good mix of carbon and nitrogen to properly decompose. Otherwise, you're either going to end up with a soupy mess or a compost pile that just isn't composting at all. Carbon rich material is referred to as brown material, while nitrogen-rich materials are referred to as green waste.

Brown waste is going to be the dry and generally non-food waste. Green waste, on the other hand, is wet and generally food waste. However, there are some exceptions. Here are a few examples of the different waste to give you an idea: 

With a backyard compost bin, you generally want to aim for equal amounts of brown and green waste. Too much of one or the other can result in unsatisfactory pre-compost. The ratio you're looking for can change with the method of composting you're doing, though.

Of course, with Lomi, you don't have to worry at all about whether you're even including any brown or green waste. You can just put whatever organic waste you have into your Lomi. Although it’s important to keep in mind that Lomi’s nutrient-rich soil amendment isn’t the same as traditional compost or pre-compost. You’ll want to choose the composting method that aligns with the effort you can put in and your end goals.

6 FAQs on composting and compostable items

While we've listed out the most expected potential compostables to help you out, there might be some specifics that are more confusing. Here are some common questions about what not to put in the compost:

1. What foods are not compostable?

Most foods will be compostable. Most don't compost meat or dairy products, as that would risk attracting pests and transferring unwanted bacteria. You also need to be conservative with the acidic food you're composting, as they can make your pre-compost too acidic.

Aside from that, you should also keep in mind the kitchen scraps that will take too long to compost compared to the rest of the organic material. Kitchen scraps in this category would be scraps like bones and fruit pits.

2. Can rotten food be composted?

This actually depends on what you consider to be rotten. Rotting is generally the start of the decomposition process, which is what you're looking for in compost anyway. Mouldy fruit and vegetable scraps are also completely safe to compost. The only rotting you should really be worried about is diseased food.

You want to avoid composting diseased food for the same reason you want to avoid composting diseased plants.

3. Is greenware compostable?

Some greenware products are advertised as compostable, but is that true? In short, it is. The catch is that they're only compostable in industrial facilities. Unfortunately, a home compost pile can't quite reach the same heat and conditions necessary to compost greenware products that an industrial facility can.

4. What plants not to compost?

There are a few occasions where you'd want to avoid putting plants in the compost bin. For one, you should avoid putting weeds that aren't dead in your bin, as you could add weed seeds to your compost pile. Weed seeds that aren't killed during the compost process could then grow in your compost or garden beds.

You also really want to avoid composting diseased plants or insect-ridden plants. Your compost pile may not get hot enough for long enough to kill the disease or insects. In that case, they could be transferred to your garden beds, which nobody wants.

5. Why can't dog poop be composted?

Whether or not you can compost dog poop, or any pet waste, actually depends on what you intend to use that compost for. Because of the bacteria that would end up in the compost, it wouldn't be safe to use the finished compost in a vegetable garden. However, you could use that pre-compost for plants you won't consume.

6. Can you plant directly into compost?

You can grow your plants directly in compost, but we wouldn't advise it. It doesn't work nearly as well as planting in a mix of compost and soil. Compost provides nutrients to plants that soil is lacking, but the same is true the other way around. Plants grown directly in compost also won't be as stable.