How To Turn a Cardboard Box Into a Garden Planter

If shipping boxes can double as imaginary forts and castles, using a cardboard box to build a gardening container will be simple.

We all love the advantages of container gardening. It offers a way for those living in small spaces to grow colorful flowers and fresh vegetables. We also know that the cost of planters and flower pots can be high, especially if you want to grow more than two or three plants. Luckily, despite its appearance, we know how to get the best results from a container plant.

If you have several shipping boxes at your house, whether from a recent move, online shopping, or monthly fashion subscription service, you already have the perfect planter for growing container plants, even edible ones. Sturdy cardboard in rectangular shapes makes it easy to arrange seeds, plus you can recycle it at the end of the season. If you want an easy gardening project to do with your children or need to start a garden without a lot of space, this is how you turn cardboard boxes into garden planters.

shipping box and flowers
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Prepare the Box

Choose a box with the width and depth needed for what you want to plant. Check your seed packets or plant tags for exact requirements. Radishes, for instance, don't need as much depth as potatoes. Choose a sturdy, corrugated cardboard box rather than thin cardboard like a cereal box. If a package has been wet or has torn sides, send it to the compost pile and find another.

Turn the box over and reinforce the bottom with one or two strips of duct tape (or a similar strong tape) applied across the seam where the flaps meet. Apply tape to any weak corners on the box as well. Fold all the flaps down outside the box and tape them down. Not only does this hold the flaps in place, but it also helps strengthen the planter's outer walls. To make your new gardening container more attractive, you can paint it, add stickers, or tie colorful ribbons around it.

Use a punch tool or large screwdriver to poke several holes, spaced about four inches apart, in the bottom of the box for drainage. If you wish, you can also line the box with a plastic bag to keep the box dry and extend its life, just remember to poke drainage holes through the bag and out the bottom of the box.

Choose the Right Spot

Set the box where you want to grow the plants before adding the potting soil. Follow the sunlight needs of the plant you wish to grow to determine the best placement. Most vegetable crops, for example, require full sun or a minimum of six hours of direct sunlight. This location will be the final spot for the plant because the cardboard will soften and become difficult to move later in the season.

How to Raise Your Garden

If you plan to fill your cardboard planter with kitchen herbs and want to keep it on a patio or deck, it is a good idea to elevate the box. You can raise the container garden by setting it on bricks or slats so that it doesn't just pool around the sides when the water drains out of the box.

Soil, Seeds, and Water

Adding Soil and Seeds

Fill the box with lightweight potting soil within one to two inches of the top. Tap the box to settle the soil. Plant seeds or seedlings in the box according to the package directions. Follow the plant spacing advice on the package to decide how many plants to place in each box.

Adding Water

Water the plants in your new garden to keep the soil evenly moist. Remember to follow watering guidelines for the specific plant you choose. Though cardboard gets wet when you water the soil, the porous, fibrous material dries out quickly, so you might need to water more frequently than with plastic and ceramic containers.

Making Adjustments

If the original box starts to break down before the end of the growing season, try to double-up by placing it into a new, larger container for extra protection–just remember to poke drainage holes in the new box. If possible, you can move the plant to a permanent spot in the ground.

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