As long as your cardboard does not have plastic coasting, it is safe to compost and is included in the browns portion of your compost.
To ensure the cardboard will break down quickly in your compost, you should shred it first.
In this article, I will talk about why shredding cardboard boxes is beneficial and list some cardboard-shredding methods. I’ll also include some helpful products as examples.
Why Shred Cardboard for Composting?
Shredding cardboard will speed up decomposition and enable you to mix it into your compost easier.
If the cardboard is added as large cardboard sheets, it increases the chance that large clumps of it will not decompose, which may lead to problems with your compost pile.
If you are adding cardboard to your worm farm (vermicomposting), then breaking it into smaller pieces will allow the worms to be able to eat it more efficiently.
Keep in mind that cardboard does not carry extra nutrients for worms, although they do love it! Just make sure that you are giving them a healthy mix of foods for nutrients.
There are a number of different ways to shred cardboard and not just ripping it up by hand.
Easy Ways to Shred Cardboard
Shredding cardboard can be a pain in the butt. It takes time and energy, and sometimes you have to do it by hand. But there are ways around this. Below I’ve listed the best methods to shred cardboard.
But first, before shredding, it is important to remove any pieces of tape, plastic, or staples because they won’t decompose.
Some gardeners do put bits of cardboard in their compost heaps with the tape still attached and then remove the tape once the compost is ready. I find it far less time-consuming to remove the tape beforehand, and shredded plastic can be tough to spot.
You can still add the staples to your heap as they will add extra iron, but if you’re using an electric shredder, you may still want to remove them to avoid the chance that they will damage your shredder blades!
1. Garden Shredder/Wood Chipper Shredder
If you’re already shredding garden waste, then a garden shredder or wood chipper is ideal for preparing cardboard for composting.
This is the best way to deal with a large amount of cardboard waste but could be overkill if you’re only doing small amounts for a worm farm. I wouldn’t recommend buying a garden shredder just for cardboard.
But if you already have one to deal with woody garden clippings, then this a chipper shredder is the way to go. Here’s a list of the best chipper shredders for composting.
Landworks Wood Chipper Shredder Electric Light Duty 17:1 Reduction 15-Amp 1800 Watts 120VAC Dual Edge Blades for Lawn and Garden Use or Fire Prevention Building a Firebreak
- SPECIFICATIONS - This All-Electric Corded Wood Chipper Shredder and Mulcher is designed w/ a durable and all-powerful 15-AMP 1800Watt 120VAC 60Hz Electric Belt Driven motor, capable of 1.5” inch (39mm) MAX Limb Chipping Capacity to 17:1 Reduction Ratio, and overall Speed of 4,100RPMs
- ECO and USER FRIENDLY -
2. Industrial Paper Shredder
Paper shredders are less costly than garden shredders, but can do the job just as easily. You’ll need to get a heavy duty paper shredder that can shred large amounts of paper at one time.
Admittedly, it is more time-consuming to use a paper shredder, and you may have to cut the cardboard down to smaller sizes first.
If you’re taking this route, go for a 12-sheet (or higher) paper shredder. Paper shredders give your cardboard a perfect consistency to add to your compost and are the weapon of choice for most cardboard composters.
Aurora AU1220XA 12 Sheet Crosscut Paper and Credit Card Shredder with 5.2 gal Wastebasket
- Crosscut with 12 sheet capacities; destroys credit cards and small paper clips
- Shreds paper, credit cards into small pieces (3/16 by 1-9/16 inches), security level P-3
- Nonstop 3-minute continuous run Tim
- Overload and thermal protection, 4-mode power switch (auto-off-reverse-forward)
- 5.2-Gallon wastebasket with LED indicator lights standby/ overheat
3. Box Cutter
If you’re cutting up your cardboard manually, you can’t go wrong with a box cutter. These sharp blades are specially designed to slice cardboard boxes.
Be very cautious with these tools, and always wear sturdy gloves when using them. The blades are often retractable, and it is worth getting into the habit of retracting them whenever you aren’t using the knife. They usually also have replaceable blades, so when the old blades become blunt, you can change them out.
Using a box cutter is the most labor-intensive method of shredding cardboard because it’s all manual. It’s best to cut the cardboard down into roughly 1-inch strips for the decomposition process.
Box cutters are also a handy tool to have if you are using a paper shredder, as they will help you cut your cardboard down to a size that fits into the shredder. But using them on their own to shred large amounts of cardboard isn’t as practical.
FantastiCAR Folding Utility Knife, Quick Blade Change Box Cutter, Anti-slip Metal Body, with Safety Lock and 5 Extra Blades (Spring Green)
- [ Stylish Plume Series ] The plume version of bright colors for you with mavericks and strong characters.The entire body is made of aluminum and the surface is polished to ensure smoothness and friction to prevent hand slippage
- [ Quick & Easy Release ] Pull out the blade
4. Electric Scissors
These are a step up from using a box cutter and will make the job more manageable if you regularly cut up small amounts of cardboard.
One tip if you are cutting corrugated cardboard to make your job easier is to cut with the grooves, rather than across them.
Cordless Electric Scissors with Two Blades - Fabric, Leather, Carpet and Cardboard Cutter - 3.6V Lithium-Ion Rechargeable Battery by Stalwart (Red)
- ELECTRIC SCISSORS - With two easy to install blades, you can complete any everyday job, home DIY task or crafting project effortlessly with the cardboard scissors. The fabric blade will cut through leather, felt, paper and fabric.
- ERGONOMIC DESIGN - The ergonomic shaped design allows for more precise
5. Electric Hand Saw
If you’re looking for something with more power and speed, you could try electric hand saws like this hand-held mini chainsaw!
It has the added benefit of being able to saw through small branches, making it perfect for pruning too.
SUNDURA Mini saw One-hand portable Mini saw 4-inch Cordless lithium electric saw Mini saw battery powered Portable for trees Powerful Cordless,Light, for trees wood cutting
- [FAST CUTTING SPEED] SUNDURA has a fast cutting speed. It takes about 10 seconds to cut round branches with a diameter of about 3.90 to 5.90 inches. It can replace the old-fashioned trouble of slow pruning branches, and greatly improve work efficiency and save your precious time.
6. Soak The Cardboard
If you don’t want to spend money on tools to help you break up your cardboard, then you can soak it and tear it up with your hands.
Soaking the cardboard also means that any stickers or tape will be much easier to remove. Cardboard that has a plastic coating, like cereal packets, will also be able to be composted if soaked. The plastic layer can be peeled away after just a couple of hours of soaking in water.
Soak standard cardboard for at least 12 hours, longer if the cardboard is thick. Once it is soggy, it will be easy to tear it into pieces.
If this seems like it would be a bit too messy for you, then you can use a garden fork. Use it to stir the cardboard in the water, which will break the cardboard up effectively. Alternatively, you could use an electric mixer.
Whether or not you dry out your cardboard is up to you, but if your compost heap or bin is too wet, then I recommend drying the cardboard pieces first to enable them to help soak up any excess moisture. Otherwise, you can give it a quick wring out, like wringing a washcloth, so it’s not too wet.
If your compost is on the dry side, then adding wet cardboard may be beneficial. If you’re using it in a wormery, wet cardboard will reduce how much water you need to add later.
7. Lasagna Gardening
While this is not a shredding method, it is still a way to use cardboard in your garden.
When adding alternate layers of organic matter to your raised bed, add one layer of cardboard in between layers of green material. It’s like layering when making lasagna.
Using your cardboard in this way is an effective way of using cardboard without cutting it down. It may also help you with your brown layers if you don’t have many woody garden cuttings to add.
8. Home Paper Shredder
This tip comes from a Smart Garden and Home reader!
Many of us have regular paper shredders at home and may not have access to the more industrial tools in the previous shredding options. A home paper shredder can still shred cardboard with a little prep work.
Most shredders can only handle a few sheets of paper at one time, so you will need to trim the cardboard to prevent jamming the shredder.
Start by cutting the cardboard into strips that are 1.5″ inches wide. Cut along the length of the “flute” (middle part). You can use scissors with this or an old-school paper cutter like this one basic one:
AmazonBasics Paper Trimmer -12" Blade, 10 Sheet Capacity
- Everyday portable paper trimmer with 12-inch guillotine-style, self-sharpening steel blade; ideal for home or office
- Cleanly cuts up to 10 sheets of 20-pound paper at a time; sharp enough to accurately trim cardstock, construction pap...
- Guardrail keeps fingers a safe distance from the blade; when not in use,
Depending on your home paper shredder, you may be able to fit wider and thicker cardboard without jamming. It’ll take a little trial and error to find the maximum size without jamming.
Shredding Cardboard Boxes Final Thoughts
There are a number of ways to shred cardboard. While some methods require specific tools, others are as simple as soaking the cardboard before tearing it apart.
The most important thing to remember when shredding cardboard is that it should be shredded into smaller pieces. This makes it easier to decompose and be digested by worms.
Here are more articles on composting ingredients:
Shredding Cardboard FAQs
Can you shred cardboard boxes?
Yes! Shredding cardboard boxes can be easy and cheap. All you need is a pair of scissors, a box cutter, and some patience. For quicker and easier shredding, you can use a chipper shredder, industrial paper shredder, and electric hand saws.
Can you shred cardboard in a chipper shredder?
Yes, you can shred cardboard in a chipper shredder. However, you should be careful when using a chipper shredder because they work by cutting the cardboard into small pieces and then crushing them. This means that the shredded paper could contain sharp edges.
How much does a cardboard shredder cost?
A cardboard can shredder cost around $100-300 depending on the size and features. For cardboard, you’ll need a high-quality, heavy duty paper shredder to be able to shred corrugated cardboard. Basic paper shredders will not be able to feed cardboard through to shred it.
Do I need to dry the cardboard after soaking it?
Whether to dry the cardboard or not depends on the situation with your compost pile. If the compost pile is already dry, then there’s no need to dry the cardboard. You can simply add the soaked cardboard directly to the compost pile. On the other hand, if your compost pile is very moist, then you might want to dry the cardboard first. The reason for this is that wet cardboard will absorb more water than dry cardboard. Soaking the cardboard will remove some of its moisture content, which will make it easier to shred.
Do you really need to shred cardboard for a worm bin?
Yes, you do need to shred cardboard for a worm bin. Worms like wood pulp, which is what makes up most of the cardboard. Worms will have an easier time eating shredded cardboard. If they can’t eat the cardboard, you won’t be able to get compost from the worm bin.