Preparing a garden bed with cardboard makes that ideal environment for the plants you intend to grow. The cardboard traps warmth and retains moisture in the soil, and forces any existing seeds to germinate. At the same time, the cardboard blocks out any light to the sprouted seeds causing them to die.
Layer 3 to 4 inches of compost on top of the cardboard. Water the compost well. Cover the space with garden sheeting to keep the soil in place and weeds from sprouting. In about 6 months, the cardboard will have broken down, and the space will be ready for planting.
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.
Depending on the time of year and what I am planting, I may cut X's in the cardboard with my spade or a mat knife and plant immediately, then mulch after planting. This would work with substantial perennials or when making a shrub border, for instance. You can certainly do this if you pre-weeded the area as above.
Add 4 - 6” of soil or compost or mulch on top of newspaper/cardboard layers 6. Allow 6 - 8 weeks for the grass under the paper/cardboard & compost layers to die back. Be patient! The longer you allow the decomposition process to take place, the better results you will see.
Cardboard takes approximately 2 months to decompose. However, instead of sending your boxes to the landfill consider adding them to your recycling or your compost pile. Cardboard breaks down fairly quickly when exposed to the elements, but stacks of cardboard can take years to decompose.
Since cardboard is biodegradable, you can add it to a compost pile. It'll break down pretty fast and serve as a healthy form of fertilizer for your soil and plants. The best part is that cardboard is entirely odorless, unlike some other items in a compost pile.
Landscaping fabric adds no nutritional value to the soil, and it doesn't decompose. And over time, the fabric can be detrimental to your soil's health. Biodegradable alternatives like shredded leaves, cardboard, and compost are healthy foods for the soil –– and the hungry earthworms!
When using cardboard as landscaping fabric, remove all staples, tape, and any inorganic material attached to your cardboard. You don't want all that extra junk polluting your garden. Make sure to overlap the pieces by a few inches at every seam, so weeds don't have any space to break through.
This no-dig garden hack is beautifully illustrated in a TikTok video from Brandon Gentry (@brandontgentry), below. Basically, you use sheets of cardboard in your planting area to kill off any existing grass and prevent those pesky weeds from popping up.
Though termites can eat some types of wood, they prefer cardboard in taste testing. If they are given no choice and have only wood to eat, they will consume it but their survival rate decreases.
Cardboard can help suppress weeds, retain moisture, and block the elements. Earthworms and other microbes LOVE cardboard! It attracts your beneficial insects and builds up your soil.
Because biodegradable fibers break down easily, roots can push through the sides of the cardboard as they grow.
Reusing Cardboard for the Garden
As a natural source, it will break down and release carbon into the soil. Garden upcycling with cardboard has many more benefits, however. You can use it as planters, to start a garden path, mulch a prepared bed, start a new bed and much more.
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. There are several advantages to sheet composting: It is an easy and uncomplicated method of composting.
In Walkways
Pull out as many weeds as you can. Then, lay the cardboard down on the ground and then cover it with a few inches of pea gravel.
The idea is to eliminate your lawn, not to keep it comfy until fall.” * Wait until fall to plant. Sheet mulching with cardboard is an inexpensive way to remove a lawn that does not require chemical application or sheets of plastic. A single layer of cardboard is laid out over the areas of lawn no longer needed.
Weeding an area that has landscape fabric is a complete pain in the you-know-what. The roots of the weeds grow through the landscape fabric making it difficult to pull them.
The most common landscape fabric is spun or woven polyester or polypropylene. Plastic is also commonly used, although it doesn't allow water or nutrients to pass through to the plants. A more eco-friendly option is made of biodegradable linen or recycled materials.
Cardboard can effectively prevent weeds from growing. It blocks the sun from reaching the leaves of the plants underneath, hindering photosynthesis and the plants' ability to grow. It's also difficult for seeds to germinate on the cardboard. However, if organic mulch is added, they may still germinate.
However, exposure to water or humidity is highly destructive toward cardboard mechanical properties. Water-soaked corrugated cardboard can easily collapse with irreversible shape distortions. Various treatments have been developed to render cardboard hydrophobic including wax layers and nanoparticle treatments.
In a home garden, cardboard used as mulch – shredded and soaked with water – the cardboard can decompose rather quickly and be completely broken down by microorganisms within 3 months.
From an environmental standpoint, cardboard needs to be recycled. Why? Because if it is put in landfills, as it deteriorates and chemically breaks down, cardboard contributes to global warming leading to climate change. This occurs as decomposing cardboard releases methane.