'I Always Save Old Cardboard Boxes to Use in My Garden' – 4 Smart Ways to Turn Trash Into Your New Gardening Secret Weapon
Are cardboard from all your online orders filling up the recycling bin? Don't toss them! Use them in your garden instead. These are my 4 favorite tricks to try.
I’m always looking for easy, budget-friendly ways to grow a better garden and one of my absolute favorite tricks is to use old cardboard boxes. Ever since I discovered the versatility of this underrated piece of packaging waste, I started recommending it to everyone I know. It seems like all the other lazy, frugal gardeners have figured it out, too.
Most of us have tons of cardboard boxes hanging around the house from all of our online orders, but instead of tossing them in the recycling bin you can recycle them in your yard and garden. They can help solve a variety of common gardening problems and, best of all, they’re free!
So whether you’re struggling with weeds, pests, or you want to expand your garden easily, cardboard is your new secret weapon. There are so many clever ways you can use cardboard in your yard, but here are my four favorite tricks to try.
1. Kill Weeds Naturally
Maybe you want to grow an organic garden or you just want to keep small kids and pets safe from harmful chemicals in your landscape. Either way, cardboard is your new best friend. Using cardboard to smother weeds is hands-down the most effective and safest way to kill weeds that I’ve ever found. And it t is so easy to do!
To kill weeds naturally, just lay down a flattened cardboard box over the area you want to cover. Overlap the sheets of cardboard by at least 2-4 inches (5-10 cm), then add a layer of mulch – this organic mulch from the Home Depot is a great option. Make sure mulch is at least 2 inches (5 cm) deep to slow down weeds.
Over time, the cardboard and mulch will break down and add organic material back into the soil. This method enriches soil nutrition and improves soil texture, similar to adding compost to your garden.
Depending on the severity of the weeds in your garden, you may have to reapply more mulch in midsummer. But if you put down cardboard early in spring before weeds are able to take root, then your garden should be mostly weed-free for summer!
2. Make a New Garden Bed
You can also use cardboard to make a new garden bed in the grass. To do this, you will follow the same method as you did above for smothering weeds. For the best results, though, you should edge out the garden bed before laying down cardboard and adding mulch.
First, use a hose or rope to trace the outline of your new garden bed. Then cut into the sod with a straight-blade shovel or an edging tool, which you can pick up on Amazon, to create the border of your new bed.
Next, lay down sheets of cardboard. You can water the cardboard with a hose or watering can to help it start decomposing faster or to keep it from blowing away on a windy day. Then add a thick layer of mulch – 4 inches (10 cm) is enough to start the process.
To plant, you can either pull away the mulch, cut a hole into the cardboard with a sharp trowel or boxcutter, and then dig a planting hole to install your desired plant. Alternatively, you can lay out your plants first, after edging the garden bed, and plant them before laying down the cardboard. After planting, carefully place sheets of cardboard around the plants and cover with mulch.
3. Create a Slug Trap
Forget using beer to kill slugs! You can make a humane, organic slug and snail trap in your garden with a piece of cardboard. Hungry mollusks can decimate a whole crop of leafy greens overnight, but I hate trying to drown them in a bowl full of beer. It just feels mean – and it never seems to work either.
A much better way to get rid of slugs and snails is to lay a damp piece of cardboard on the ground in your garden next to the mollusks’ favorite plants. They tend to go after leafy plants like hostas and lettuce or brassicas like broccoli and cabbage.
Leave the piece of garden in your garden overnight, then in the morning pick it up and it should be covered in slugs and snails. Carefully remove the pests and toss them far away from your garden.
4. Fill Raised Beds for Free
If you just built or bought a new raised bed, then it’s time to start stocking up on cardboard. Don’t waste your money on landscape fabric to line the bottom of your beds. It just breaks down and gets tangled up with weeds, eventually causing a much bigger problem than it ever solved.
Leaving the bottom of your raised bed open to and accessible to the soil underneath also allows plants to grow deeper root systems and hold onto moisture longer, which means less watering – yay! Instead of using landscape fabric to stop weeds growing up in your beds, grab those old cardboard boxes out of your recycling bin.
Flatten out the boxes and lay them at the bottom of your raised bed. This will stop weeds from growing up through the soil once you fill your raised beds, but it will eventually break down and let your plants’ roots grow deep into the native soil.
You can use cardboard as the base layer in a hügelkultur raised bed. After placing the cardboard, layer on logs, cut branches and brush, then add compost, your preferred soil mix – I always have good results with Miracle-Gro potting soil from Home Depot – and plant. Your beds will be weed-free and thrive all summer long with less watering.
