DIY Concrete Planter

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This old filing cabinet was taking up space in our detached garage and my husband wanted it gone. Rather than paying to haul it to the dump and creating more waste – I decided to upcycle it into a massive concrete planter. I absolutely love how this project came together – click here to see my instagram highlight.

Here’s everything I used:



  • Drill/Driver
  • Saw
  • Square Trowel
  • Paint brush
  • Large bucket

First I removed the drawers and lightly sanded the outside of the cabinet. Then I applied a stone texture spray paint to what will be the top of my planter. I did this because I will not be able to attach cement board to the top – so I wanted a textured surface for the mortar to (hopefully) stick to.

After that, I cut my cement board to size. You can either measure, or simply line up the board with the filing cabinet, and trace where you need to cut. There are several ways to cut cement board. I used a box knife to score, then snapped the excess off. Be sure you score deep enough before you attempt to snap otherwise your cement board will crack.

Once I had all of my pieces trimmed to size – I stuck them to the sides of the filing cabinet with liquid nails. Make sure the rough side is facing out because that is what your mortar will stick to. Additionally, If you have any rust on your filing cabinet, be sure to sand and coat it with something (like flex seal) that will prevent further damage before applying the panels.

Now it’s time to attach the panels with screws. It may seem tempting to use whatever screws you have on hand but cement board screws are corrosion resistant and made specifically for cement board. I highly recommend using them for this project.

You’ll need to drill pilot holes first to get the screws through the metal. Because the screws are longer than the thickness of the cement board + filing cabinet – I cut down some cedar 1 x 2 boards to line the inside. Now I won’t have screws poking through on the inside of the planter. Also make sure your screw heads are flush or just below the surface of the cement board.

Once everything is securely attached, caulk the seams with paintable (outdoor) caulk. Once that is dry go over your seams with mesh cement board tape. I went over the corners, as well as along the bottom edge where my cuts were made to keep the raw edge in tact.

Grab a bucket and mix your mortar according to the package. I chose a gray color but there are other options to choose from! Use a square edge trowel to apply a thin layer of mortar to the outside of the cement board. Once it starts to dry, scrape away any excess and use a paint brush dipped in water to smooth any imperfections. If you want a more textured look, skip the paint brush or you can use the paint brush to create a fun texture. Have a little fun with this part and get creative! You’ll probably need to do 2-3 coats of mortar.

Once it’s dry, lightly sand to remove any unwanted rough spots with a 80 grit sanding block, then seal the mortar with a concrete sealer to protect it from the elements. Drill holes in the bottom for drainage. Then for good measure, I also sprayed the inside with a coat of flex seal to help prevent any possible corrosion. The inside is not the cutest which no one is going to see anyways, but I think if I were to go back and do it again I would tape off the top, and use black flex seal on the inside instead.

I am totally obsessed! I have the perfect spot picked out – now I just need to figure out what I want to plant in it! If you try this DIY, don’t forget to tag me. I LOVE to see your creations!

Side note: this planter will be SUPER heavy – I recommend filling the bottom with something lightweight (like cut up pool noodles, or empty milk jugs). This will not only help with drainage, but it will also keep you from having to fill the entire thing with dirt.

Published by houseon610th

Wife | Mommy | Dog Lover | Graphic Designer | Lake Rat

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