Porch Deck and Patio

Porch, Deck + Patio

Outdoor Projects

How to Build a Planter Box for Your Porch

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Chelsea Lipford Wolf Expert Blogger 4 Projects

All the tools and materials you will need are pictured below.

Planter Box1

I've always loved the look of a window box full of blossoming flowers. But having a vinyl-sided house makes installing one a big commitment-since you can’t just putty and paint holes in vinyl like you can wood or drywall.

Luckily for me though, window boxes also work well on deck and porch railings! So I set out to build one for my front porch.

Planter Box Before1

I started with a plastic window box insert I found at a local home center. My plan was to create a wooden “wrap” that the insert could drop in to. I started by cutting all of the lumber.

Planter Box2

Here’s the breakdown of how everything was cut:


-25 ½

-9 ¼ (x2)

-23 ¾


-25 ½

-9 ¼ (x2)

-23 ¾

Now let's begin.

Building the Planter Box

  1. I started by cutting all of the lumber.

    Planter Box2

  2. Once everything was cut I set the 9 ¼ inch 1x8 on their short end about 24 inches apart. And with a little exterior wood glue on each end, I set the longest 1x8(25 ½ inches) on top.

    Planter Box3

  3. Making sure the edges were flush, I attached a 1 5/8 inch deck screw in each corner.

    Planter Box4

  4. Then I came back and added another screw in the middle, making sure the spacing of the screws was aesthetically-pleasing since it would be the front of the finished planter. This is also a great reason to use tan deck screws versus the grey-colored exterior screws.

    Planter Box5

    With 3 sides down, there was only the back piece left to go. It slid between the two sides and was attached by going through the side pieces. I used 3 screws again for each end.

  5. With the main part of the box assembled, I took the 23 ¾ piece of 1x2 to create the actual “support” for the window box insert. You can see the insert has some “feet”, but the 1x2 easily sits in the middle between them.

    Planter Box6

  6. So I set it flush with the bottom of the wood box and centered. Then using 1 screw each I attached it from both sides.

    Planter Box7

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  7. To make it a little fancier, I used the 1x2 to create some trim. I wanted it to have a ½ inch overhang on the front and 2 sides, so they needed to be flush with the inside edge of the 1x8 pieces. It's a little difficult to nail tiny finish nails and hold the 1x2 in place, so I pre-nailed them the entire length.

    Planter Box9

    Then I held it flush with one hand and nailed with the other. The 2 side trim pieces were nailed the same way, but I made sure they were flush with the back of the box as well as the inside

  8. Then it was time to switch to the sander!

    Planter Box10

  9. I used the 240 grit that came with the sander attachment since it just needed a little smoothing before the waterproofer was applied with a paint brush.

    Planter Box11

  10. While the waterproofer was drying, I planted some fall-blooming flowers in the insert.

    Planter Box12

  11. When it was time to install the box, I held it up centered on my handrail and marked where the railing spindles were located.

    Planter Box13

  12. Using 2 inches screw at a slight angle, I drilled them into the box just enough so they were barely poking out the back.

    Planter Box14

  13. Then I held it up the railing again and screwed them into the spindles. I used 4 screws total.

    Planter Box15

  14. And with the insert set in place, it was time to sit on the porch and enjoy the view!

    Listing Image