How to Build a Cedar Planter Box Square

Building a cedar planter box square is a great DIY project that can add some natural charm to your outdoor space. You'll need to start by choosing the right type of cedar, Western Red Cedar is a popular choice due to its durability and resistance to rot and insects.

To build a square planter box, you'll need to cut four pieces of cedar to the same length, which is typically around 8 feet long. This will give you the frame for your planter box.

Next, you'll need to cut two more pieces of cedar to the same width, which is usually around 6 feet long. These will be the sides of your planter box.

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To build a cedar planter box square, you'll need to gather some essential materials, including cedar lumber, a saw, a drill, and a measuring tape.

Cedar lumber is the primary material for building a cedar planter box square, and it's available in various thicknesses, including 1/2 inch and 3/4 inch.

Choose a saw that can handle the thickness of the lumber you've selected, and make sure it's sharp for smooth cuts.

A drill is necessary for creating holes for drainage and assembling the box, and a measuring tape will help you ensure accurate measurements.

To prepare the lumber for assembly, cut it into the required pieces, including the sides, bottom, and back of the box.

The sides of the cedar planter box square should be cut to the same length, typically 24 inches, while the bottom and back pieces should be slightly shorter, at 22 inches.

Assembling the planter box is a relatively easy process, especially if you're using cedar fence pickets. You'll need to start by butting two of the 18 3/16″ picket boards up edge to edge.

To assemble the sides of the planter box, you'll need to lay two of the 12 1/2″ 1×2 pieces on top of the picket boards, aligning the legs to the top and sides. Use wood glue and brad nails to hold these pieces together.

It's essential to create two of these assemblies to form the sides of the planter box, which will then be glued and nailed together.

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Assembling the Planter Box requires a few essential tools to get the job done. You'll need a table saw, miter saw, or circular saw to make precise cuts in the wood.

A table saw is a great choice for making straight cuts, but a miter saw or circular saw can be more convenient for angled cuts.

You'll also need an 18 gauge brad nailer to secure the wood together. This type of nailer is perfect for small, delicate projects like a planter box.

To attach the wood, you'll need 1″ exterior grade brad nails. These nails are specifically designed for outdoor use and will withstand the elements.

A pocket hole jig is also necessary to create strong, hidden joints. This tool will help you make precise holes in the wood for a seamless finish.

Exterior grade wood glue is essential for bonding the wood together. This type of glue is specifically designed for outdoor use and will withstand the elements.

Finally, a sander and sandpaper are necessary to smooth out the wood and prepare it for finishing.

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To start assembling the sides of your planter box, you'll need to cut and prepare the cedar picket boards and 1x2s. You'll need to cut four 18 3/16″ picket boards and seven 17″ picket boards, as well as some 1x2s and 1x3s.

You can use a miter saw to cut these pieces quickly, especially if you set up a stop block. This will help you make precise cuts and save time in the long run.

Butting two of the 18 3/16″ picket boards up edge to edge is the next step. Then, lay two of the 12 1/2″ 1×2 pieces on top and use wood glue and brad nails to hold them in place. This will create the frame of your planter box.

To attach the 1x3s to the outer edges of the 1x2s, you'll need to nail from the outside of the 1×3 into the 1×2. This will provide additional support and stability to your planter box.

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Here's a summary of the pieces you'll need to cut and assemble for the sides of your planter box:

Remember to use wood glue and brad nails to hold the pieces together, and make sure to align the 1x2 legs to the top and sides of the picket boards. This will ensure a sturdy and secure frame for your planter box.

To assemble the cedar planter box squares, start by lining the bottom with a folded sheet of newspaper or recycled kraft paper to prevent soil from falling through the cracks.

This will allow the water to drain out as needed while keeping the soil in the box, and it also helps prevent weeds from coming up. I found this to be an effective solution for my project.

Place the boxes on a flat surface, such as a deck or patio, but be aware that placing them in the grass will kill the grass beneath them.

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Finishing touches are where the magic happens. Use at least 120 grit sandpaper to lightly sand the entire piece.

Pay attention to the inside of the box, where moist dirt will stay in constant contact with the wood. This area needs extra protection.

You have several options for finishes, including stain and exterior grade paint. Choose the one that suits your style and needs.

For a more eco-friendly option, consider checking out our series on eco-friendly wood finishes. We detail various options, including oils, waxes, and plant-based solvents.

Don't forget to apply a few coats of your chosen finish to ensure proper protection from the elements.

To prevent soil from falling through the cracks in your planter boxes, line the bottom with a folded sheet of newspaper or recycled kraft paper.

This will allow water to drain out as needed while keeping the soil in the box, and also help prevent weeds from coming up.

You can place the boxes on the ground, a deck, or a patio, but keep in mind that putting them in the grass will kill the grass beneath them.

It's a good idea to arrange the boxes based on the space you have, and don't worry too much about making perfectly straight cuts - rustic planter boxes are just fine.

Assembling the boxes should take no more than 5-10 minutes, depending on how carefully you make your cuts.

Using cedar fence pickets, you can make window boxes and rectangular planter boxes in addition to square ones, like the author did.

It's a good idea to put a little more soil than you think you need into the planter boxes, as it may get tamped down when it rains.

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