Cardboard is certainly a welcome sight in the eye of the gardener.
Often free and fairly ubiquitous, cardboard is a biodegradable and earth-friendly material that enriches as it breaks down.
Cardboard is a valuable source of carbon, one of the building blocks of life. As it decomposes, it supplies vital energy to the microbes that improve soil quality and structure.
Be selective when using cardboard for outdoor purposes. You’ll want “clean” stuff – plain brown corrugated cardboard with minimal printing on the surface. It should be unwaxed and non-glossy with any tape and stickers removed. Although, you’ll find that Amazon Prime shipped boxes include compostable tape.
With the rise of online shopping, it seems there’s always a constant stream of cardboard coming through the home. Don’t send it for recycling, instead put it to good use in the garden!
1. Sheet Mulching
Sheet mulching is also known as “composting in place” because cardboard is made up of carbon while grass and weeds add nitrogen. As it degrades, it will nourish the soil.
2. Suppress Weeds
Cardboard as a weed barrier should last a season or two before needing to be replaced. And unlike landscaping fabric made of plastic, cardboard won’t prevent nutrients or beneficial organisms from working their magic within the soil.
3. Garden Cloches
Corrugated cardboard boxes offer the most protection against chilly conditions. These have pleated sheets sandwiched between two flat pieces of linerboard, which helps trap cold air for better insulation.
Like dried leaves, straw, and wood chips, cardboard is a bulky material that is high in carbon. And you’ll need quite a lot of it to keep the microbes fat and happy. Shred or tear it up into 1-inch squares to help speed decomposition along.
5. Seed Starter Pots
Cardboard toilet paper tubes are the perfect size and shape for making little seed starter pots. Just make a few small cuts at one end and fold the flaps in to make a bottom. Add soil and plant your seeds.
6. Container Gardening
Lasting just one season, cardboard planters can tide you over until you can build the garden of your dreams. They also lend themselves well to a child’s garden space. And when the season is finished, shred them up and toss in the compost.
7. Potato Box
All sorts of materials can be repurposed into a potato growing container – including cardboard boxes. Keep the bottom of the box intact or open up the bottom flaps for potatoes planted directly in the soil. Add drainage holes if needed.
8. Square Foot Gardening
Cardboard boxes can be clustered together in any open space in the yard. Be sure to elevate them and add drainage holes.
9. Tree Protectors
Paper tree protectors are ideal for insulating against hot and cold weather and will thwart attempts to girdle your baby tree by rabbits and deer.