How to Shred Cardboard for Compost? Simple Instructions and Tips!

Cardboards offer the best carbon source to create compost. Continue reading this article to discover how to use cardboard for your compost heap.
Nora Held
Nora Held
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Creating a very good compost pile requires the use of certain carbon sources like autumn leaves, wood chips, sawdust, or twigs to derive a solid form. However, these materials are usually hard to find in different climate conditions. You may not know this, but cardboard is a great carbon matter and serves as an excellent alternative to other materials. Using cardboard for this process can, however, be quite tricky as it doesn’t naturally come in the same form as other carbon sources. This is why you need to know how to shred cardboard for compost. This article breaks down the need to shred cardboard for your compost pile and how to carry out this process.

Why shred cardboard for compost?

How to Shred Cardboard for Compost? Simple Instructions and Tips!

Many often wonder whether or not it is imperative to shred cardboard for compost. In the absence of any other carbon matter, cardboard offers a great option for making compost but requires shredding before use. Unlike other natural carbon sources such as wood chips, barks, and dry leaves, cardboards come in the form of boxes and large size of packaging that will not be suitable for this process.

The materials needed in making compost need to be smooth enough to speed up the decomposition process for a solid pile. However, using large and bulky materials will make the entire process difficult by reducing the surface area, which slows down the decomposition.

Cardboard is naturally made from woody pine trees. This means that the shredded form gives the similar carbon source you get from dry leaves and sawdust. You have to take into account the structure of the cardboard you plan to shred. If there is plastic or any other material attached to the cardboard, you must separate it from the shredding process to avoid ruining the compost.

How to shred cardboard?

There are various ways you could cut your cardboard into pieces for compost. Cardboards are mostly free and available around. There is no doubt you will find some lying around from deliveries and packages in your basement. You could also pick up some free cardboards at wholesale retailers, bookstores, recycling points, or office depot. Let’s look at some of the methods of shredding your cardboard.


How to Shred Cardboard for Compost? Simple Instructions and Tips!

Using a shredder to shred cardboard is no doubt the easiest and most effective method available. A paper shredder does a good job at cutting paper and cardboard into very small pieces. The shredded pieces of cardboard from the shredder are usually even and suitable for compost creation. Always remember to remove any plastic before you put cardboard into the shredder to avoid any unwanted particles in your compost pile.

Classic shredding method

How to Shred Cardboard for Compost? Simple Instructions and Tips!

The classic shredding method is a straightforward and pretty common shredding process that requires a sharp tool such as a pair of scissors or a box cutter to cut the cardboard into smaller pieces. To get started, you must remember to separate any plastic and non-carbon material attached to the cardboard. With a pair of scissors or a box cutter, you can cut the cardboard into 1 inch. However, it would be best to use a shredder for a quicker and easier shredding process.

Wetting method

How to Shred Cardboard for Compost? Simple Instructions and Tips!

Shredding cardboard when it is wet is one of the easiest ways to get it done. Having a wet package can be annoying and hard to deal with but not in this situation. You will find it quite easy to shred cardboard into pieces when wet. There are various ways you can get your cardboard wet. One way to go about this process is by soaking the cardboard in a basin or large tub. After a few weeks, the cardboard once will be soft enough, which means you can shred them with your hands.

If you live in regions with high levels of precipitation and rainfalls, you could alternatively leave the cardboards out while the rain falls.

Tips and tricks

Shredding cardboard is relatively easy, and you should encounter almost no issues. Nonetheless, we have provided some tips to help you get the best result from this process.

Chemically treated cardboards

You want to ensure you maintain the potent carbon source from your cardboard for your compost. You must avoid cardboard with chemical components as this will pose a danger to your compost pile. Chemicals such as ink could ruin your compost. Remember to always clean your cardboard before shredding.

Synthetic substances

When shredding cardboard for your compost, you want to ensure you get just the materials from the carbon source. You should check for synthetic substances like plastics before shredding. It would be best to also flatten the cardboard to shred it easily. If you choose to apply the wetting method, it would be much easier to remove the plastics once the cardboard is wet.


You must note that it may take a while for decomposition to occur. However, shredding your cardboard into very tiny pieces will make things faster. Using a shredder like the SuperHandy Leaf Mulcher to shred the cardboard will effectively speed up the decomposition, and your compost pile should be ready within a few months.

Benefits of cardboard shredding

How to Shred Cardboard for Compost? Simple Instructions and Tips!

Composting has allowed many people to deal with green waste themselves. Making compost requires two essential materials, which include a carbon source and a nitrogen source. Cardboard already provides a solid option for a carbon source, but you must cut it into tiny pieces before use. Here are some reasons why you should shred your cardboard for compost.

Easy breakdown

Cardboard comes in chunky boxes and sizes that aren’t suitable for making a compost pile. Shredding cardboard breaks down the components into tiny pieces that will quicken decomposition and help the compost pile. Non-shredded cardboard will be clumpy and useless to the compost.

Reducing odor

A compost pile comprises carbon materials and nitrogen sources. These nitrogen sources often produce foul odors due to the amount of food and other oily substances used for compost. Luckily the original carbon content of the cardboard helps to dampen any offensive smell once shredded and added to the compositing system. Using Shredded cardboard provides quick decomposition and reduces any odor. The Worm Factory 360 is an excellent compositing system that allows you to create your compost effectively.

Providing air space

When creating compost, your mixture must give enough room for aeration. Getting enough oxygen is good for your compost to create adequate microbial action, which is what shredded cardboard offers. Shredding your cardboard makes the pieces lighter to create space for aeration of the compost pile.


Below are some of the constantly asked questions about cardboard shredding for compost.

Can you shred cardboard that has food stains?

Yes, food strains contain a level of nitrogen which is a major ingredient in creating compost. Food strains on cardboards will add some quality and a rich blend to the compost heap.

Does cardboard supply any nutrients to the compost?

Yes, cardboard acts as a carbon source which is one of the primary components needed to create solid compost.

Can any type of cardboard be used for composting?

You can use any cardboard to create compost as long as there are no synthetic or chemical substances on them, as this may damage your composting.

What to do if cardboard is too hard?

If you have hard cardboard, it would be best to use the wetting method to soften the texture. You can leave it soaked as long as possible until it is soft enough for shredding.

Can you use paper scissors for shredding?

Yes, paper scissors are a good alternative if you do not have a shredder, chipper, or box cutter.

Final thoughts

It is not every day we get dry leaves and other natural carbon sources necessary for composting. While cardboards provide a reliable alternative to these materials, shredding them is essential to creating good compost. Now that you know how to shred cardboard for compost, you will be able to create a solid compost pile using the carbon source from well-shredded cardboard.

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