Can You Use Shredded Cardboard As Mulch

Can You Use Shredded Cardboard As Mulch – There Are More Ways Than One

Whether you’re new to gardening, or you’re an expert, it never hurts to use tips and tricks to bring more life into your plants. Mulch is a great addition to your soil to help retain moisture and keep the soil temperature cool enough to be ideal for growth. It also prevents the big bad weeds from taking shelter in your garden, and even protects your plants in the wintertime. 

The best part? You can repurpose household items as mulch, including cardboard. In fact, it’s one of the most ideal materials to amp up your gardening. 

There are a couple of ways you can use cardboard in your garden! Mulch is one of them together with shredded cardboard for composting!

Let’s check why and how cardboard is so good!

Does cardboard make good mulch?

There are many things cardboard is useful for – packing things for a big move, storage, crafts, and gardening! Cardboard is a game-changer for making your soil stronger and healthier. It is a great addition to composting or worm farms.  

Retains Moisture

When added to soil, cardboard is extremely effective at retaining moisture by preventing it from evaporating into the air. This keeps the soil at an ideal moisture level, allowing your plants to thrive even in tough conditions. 

Feeds the Soil

Shredded Cardboard

Cardboard as mulch attracts the right attention. Worms make their way to the soil to feast on their latest meal and will support the breakdown of the cardboard into your soil, giving it the strength it needs to make your garden flourish. 

Prevents Weeds From Growing

Thriving plants are exactly what we want – EXCEPT when they’re weeds! Placing sheets of cardboard across your soil prevents weeds from getting the light they need to grow, preventing them from causing further damage. 

How to Use Cardboard for Mulch

Shredded Cardboard 

Most items, including cardboard, break down much faster when in smaller pieces rather than single large pieces. This is because the smaller pieces are quicker for organisms to feed on and decompose. You can simply cut your cardboard into smaller pieces, or use a paper shredder to really get it into strips. Once that is done, simply spread the strips around your soil. You can stop there, or add a mix of other mulch items which will make your mulch more beneficial to the soil. 

That being said, if your garden is prone to weeds, then shredded cardboard may not be ideal. This is because shredded pieces are not large enough to cover weeds and block out sunlight, allowing them to continue to grow through the mulch. This is where sheets of cardboard are more ideal. 

Sheet Cardboard

Sheet mulching is one of the most effective ways to trap moisture within soil. The process is quite simple: cover your desired area of soil with large sheets of cardboard side by side, and then layer more mulch on top to make sure the cardboard doesn’t fly away or dry out. 

Keep in mind that if you’ve already planted fruits, veggies or anything else, you’ll want to place the sheets AROUND rather than directly over them, so they’re not squashed. 

Woman With Mulch In Hands
Dvortygirl, CC BY-SA 3.0, via Wikimedia Commons

What Cardboard NOT to Use As Mulch

If you’re using cardboard that has served another purpose in the past – delivered your last impulse online purchase or is leftover from your recent grocery run – you’ll want to make sure it is in ideal condition before throwing it directly into your soil. 

Many cardboard boxes, especially those with branding, will have plastic coating or ink printed on them. These are both NOT biodegradable materials nor are they healthy for your soil. A lot of boxes for deliveries are also covered in tape, another item that you want to avoid. So before laying down your cardboard, make sure you’ve cleaned up any unfavorable materials. 

Frequently Asked Questions

Can I compost cardboard?

You can use cardboard to make your garden healthier in more ways than one. Not only is cardboard great to use as mulch, but you can also add it to your compost pile, so long as it’s clean and doesn’t have any additional non-biodegradable materials. 

Can I use other materials for mulch?

There are many other materials that can (and should) be used as mulch. In fact, using other organic items alongside cardboard will improve your mulch significantly. Ideal additions include straw, wood chips, pine needles and even leaves. 

How long does cardboard take to break down as mulch?

Cardboard on its own can take 3-6 months to break down. This will vary depending on the conditions – if your cardboard is accompanied by other materials, or is part of your compost, then it is likely to degrade much faster. This is also the case if the soil and air are warm enough. If not, the cardboard may take longer, but will eventually break down.