/ / Build a square planter box from cedar

Build a square planter box from cedar

It feels like you’ve been driving around in circles for hours, checking off your never-ending errands list. 

It doesn’t help that you forgot your grocery list at home. You certainly did not relish that extra hour trudging down each aisle with a packed shopping cart, visualizing the list that you wrote last night. 

Then, as you finally scramble out of the overcrowded supermarket, the torrential downpours start. 

You feel your stress levels rising faster than your umbrella, the one thing you did remember.

As you sluggishly pull into your driveway, you can’t help but stare at your sad front porch. 

Nothing reflects your mood better at the moment….an empty little space with no design elements, tired and uninspired.

Our front porch lacked charm as well. 

One day, as I walked up to the front door of my house, I had a sudden flash of determination. It might be a tiny space but it should not be neglected.

I thought of a fun project, to build a planter box, that I could use all year long and add curb appeal to our home. 

Here is the planter box I built:

simple cedar planter box

What do you think? The best part about this project was how easy it was to build! Read on to find out how to build your own planter box.

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  • miter saw
  • Kreg Jig
  • drill
  • clamps
  • sander (optional)
  • safety glasses
  • face mask (for dust)
  • ear protection

You can print the material list and instructions below.



To help you with this project, I created some free printables. You will have to subscribe to my newsletter to receive the FREE PDF, fill out the form below if you’re interested. Or if you have questions, please visit the Q&A page on free printables/plans.

Or grab a copy of the premium printable plans to build this project by clicking the button below. The premium plan walks you through every step of the build, with detailed diagrams and clearly written instructions.


Once you’ve purchased the supplies, the first thing you need to do is cut the wood.

cutting boards for planter box

Here are the lengths and how many cuts you will need for this 18″ planter box:

  • 16 – 16.5 inches 2×4 (sides)
  • 4 – 3.75 inches 2×4 (legs)
  • 2 – 15 inches 2×4 (bottom)
  • 2 – 7.5 inches 2×4 (bottom)


 using mini Kreg Jig pocket maker

Now, add pocket holes to the 2×4’s where you will attach the wood pieces together. 

Lay the 16.5 inch 2×4’s on a flat surface, in groups of four. These will become the sides of the planter box.

SIDE NOTE: I labeled each side and where the board was (1st, 2nd, 3rd, and 4th).

boards for square planter box

Next, on the top and third board from the top (1st and 3rd), add two pockets on the left side. For the second and fourth board, add two pockets to the right side. 

Then, for the second, third, and fourth boards, add two pockets to each end (about 2-3 inches away) from the long top side. 

All the pockets should look something like this:

layout for planter box

Repeat this for all four sides.

Next, add two pockets to the top of the legs.

After, add two pockets to the 15-inch board along the long side. Then, add two pockets to each end of the 7.5-inch board. 

To make this process easier, please scroll up and subscribe to my newsletter to receive the free plans on this build. 


When you’re ready to assemble the sides together, you will need two 16 inch clamps or a wall with some scrap boards. I used a wall and it worked great!

Start by placing board ONE along the wall with the pocket holes facing up and to the right. Next place the SECOND board against board one with the pockets facing the first board. Then place the THIRD board with pockets facing the previous two boards and finish with board FOUR again having the pockets facing the last board. 

Now you need to space the layers to allow for the side pieces to fit together like a puzzle. The best way to achieve this space is to use another 2×4 piece and place it where the side pockets are on each board.

SIDE NOTE: These side pockets are where the sides of the planter will be attached together.

assemble sides of planter box

Use the 2.5-inch screws to attach the boards together to create side ONE of the planter box.

sides of planter box

Continue this process until all four sides of the planter box are created. 

Once all the sides are assembled, it’s time to create the box. 

Place side ONE on the ground and place side TWO into the gaps (have side TWO against the wall). Attach the side together with the 2.5-inch screws.

attaching side of planter box together

Continue rotating and adding sides until all the pieces are connected. Make sure to use every pocket!

square planter box


Now it’s time to attach the support to hold the square plastic planter inside the wooden box. 

Place the wooden box upside down on a level surface. Then, place the plastic planter inside the box, upside down as well. 

Take the 15-inch 2×4 board and mark where it needs to be attached by laying it across the plastic planter.

SIDE NOTE: I wanted the plastic planter to be 1/4 inch lower than the wooden box, so I measured the distance and took off a 1/4 inch. My distance came out to 1.25 inches.

Mark one side (on the inside) at this distance. Then, attach the 15-inch board to that side with 2.5-inch screws. 

Complete this step on the opposite side as well.

base of planter box

Next, attach the 7.5-inch boards in between the two boards that you just added but about 2-3 inches away from the sides. It should look something like this:

support for base of planter box


Now, let’s add the legs while the box is upside down. 

Choose one side of the box to be the front. Make sure the bottom of the legs are level; if not, use a sander to level (you don’t want wobbly legs).

Then, attach two legs on the front side of the planter with the pockets facing the inside of the box. 

Finally, connect the other two legs to the opposite side in the same way. 

SIDE NOTE: In the picture below, the legs originally faced different directions. Afterwards, I had a change of heart. I move the legs so they all face the same way and this solved my design problem.

adding planter box legs


If you want to skip waterproofing the wood, your box would now be complete. But if you want it to last in any kind of weather, stain/waterproof the wood now. I used Ready Seal in Natural Cedar, the same stuff we used on our fence and mailbox post.

Another thing you can do is add pocket plugs into the pockets (I would suggest the top boards and maybe the legs) although this step is not needed. I have found it better to stain these first and then glue them into place.

The box is now complete. 

And the next time you arrive home after a hectic morning, you will be greeted with a cheerful wood planter box, holding gorgeous seasonal flowers or foliage.

DIY square planter box


I love knowing how much a project will cost before I start. Here is a cost breakdown minus tools and stain:

  • 2×4’s = $24 ($8 each)
  • 2.5 inch screws = $9.50 (about 85 screws)
  • plastic planter = $8

TOTAL COST = $41.50

So, for less than $50, you can build a custom wooden planter box. What do you think? 


Are you someone that does better with visuals? Check out the full project video below and don’t forget to subscribe on YouTube so you don’t miss out on future projects!

Yield: planter box

Build a Planter Box from Cedar

How to build a simple planter box

Do you want to add curb appeal to your porch? Why not build a planter box from cedar may be something simple that catches a person's eye. Here are the steps:

Prep Time 10 minutes
Active Time 5 hours
Total Time 5 hours 10 minutes
Difficulty Moderate
Estimated Cost $50


  • 4 – 2″x4″x8′ cedar boards
  • 78 – 2.5 inch outside wood screws
  • stain/waterproofer
  • exterior wood glue
  • pocket plugs (optional)
  • 14″ square planter (at the widest point 14.5 inches)


  • miter saw
  • Kreg Jig
  • drill
  • clamps
  • sander (optional)
  • safety glasses
  • face mask (for dust)
  • ear protection


  1. Cut the cedar boards according to the plans.
  2. Add pocket holes to the cut pieces.
  3. Assemble the side pieces of the box.
  4. Attach the side pieces into a box.
  5. Attach the bottom supports to the box.
  6. Add legs to the box.
  7. Stain/waterproof the planter box.
  8. Enjoy!
build a planter box


  1. Stephanie says:

    Having a hard time locating 2 x 4 x 8 cedar boards. Would this design work with 1 x 4 cedar boards? If so, what size wood screws would you recommend?

    1. I found mine at Home Depot. You could use a 1×4 and I would recommend using a 1-1/4″ screw with that size of board, hope this helps!!!

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