Why I don’t like cardboard mulch (2024)

FAQs

Why you shouldn't use cardboard in the garden? ›

A: In addition to interfering with water and gas movement into the soil environment, corrugated cardboard has chemical contaminants that you really don't want in your soil or even your compost pile.

Using cardboard or newspaper as a natural weed barrier can allow you to kill a very large area of weeds and grass without using any chemicals or herbicides. Cardboard is applied to the area. Then a layer of mulch goes on top of that. In creating a highly fertile site, a gardener may put several layers of materials.

They tend to hinder to air and water movement, most especially in unmanaged landscapes like restoration sites. A classic example is the use of cardboard or newspaper covered with wood chips. The chips are easily dislodged, exposing the sheet mulch which quickly dries out and becomes hydrophobic.

The cardboard layer breaks down after several months (depending on soil type and geographical region) and the mulch will begin to decompose through contact with the soil.

In published comparison studies, other mulch choices generally outperform cardboard in terms of plant growth, weed control, etc. But there's one area where cardboard is tops compared to every other mulch material tested. Termites. Termites LOVE cardboard.

Both landscape fabric and cardboard weed barriers are good options for blocking weeds, and they can even be used together—landscape fabric can be used as the bulk of the protection, while cardboard can be laid down on the top of beds each year to provide a second layer to help keep weeds out during the off-season.

Disadvantages of Mulching

Excessive mulch that is a layer more than 3 inches deep can suffocate and bury plants. In this case, oxygen and water are unable to reach the roots. A layer of 2 to 3 inches of mulch is enough.

It does all of the things that regular mulch does, but even more effectively. Deep sheet mulching also suppresses weeds and relies on natural composting processes to change multiple layers of organic material into soil where new plants will grow.

If you initially put down 3 inches of mulch – our recommended amount – it should take about 1 year to decompose. The good news is that the mulch is feeding your soil as it decomposes.

Yes, roots can grow through cardboard, but only in certain conditions.

How do you compost cardboard faster? ›

It is critical that all cardboard to be composted is broken into small pieces. Large pieces will not decompose as quickly. Also, soaking the cardboard in water with a bit of liquid detergent will help to speed up the decomposition process.

Shred the cardboard and add it as an important carbon source to your compost bin. Another idea for reusing cardboard for the garden is to place pieces of it around plants in areas that are prone to weeds. It will reduce weeds drastically and eventually compost into the soil.

Secondly, since brown cardboard is often used to hold and transport organic foods, there is undoubtedly a small amount of food juices and rotting waste that seeps into the cardboard. This means you have a good chance of finding a microbial population in the cardboard and we all know worms love microbes.

Cardboard is better than newspaper because it does not contain ink and is more durable. By layering flattened sheets of cardboard around your planting area, you can eliminate grasses and other surface vegetation on your turf by smothering them.

Use uncoated, undecorated, plain brown cardboard boxes- as large as possible for ease of use- and with the packaging tape removed. Avoid using shiny, plastic-coated or waxy coated card or cardboard as these are likely to contain environmentally unfriendly chemicals.

Yes, roots can grow through cardboard, but only in certain conditions. 'Firstly, the cardboard must be moist enough to allow the roots to penetrate it. Second, the cardboard should be placed in a place where there is no light or air circulation,' Melody says.