The back deck on our small cabin needed some plants! I wanted to keep them off the actual deck surface to protect the redwood from rot and avoid taking up actual deck space, so I thought up these quick, easy, inexpensive DIY floating guardrail deck planter boxes. Let me show you how to put these together in no time. But first, here is a photo of the installed deck planter boxes that float off of the guardrail.
Planter Box:
The black resin planter boxes were bought at Home Depot, found here. They were under $13 per box with the measurements listed as 7.86 in width x 23.75 in length.
I removed the bottom water tray and drilled a few more drainage holes in the base to ensure good drainage, filled in some soil, and added two small English lavender plants. I love lavender flowers, and they make a delicious lavender-blackberry-lemon pie! Maybe I’ll post the recipe for that later. Comment below if you’d like it.
Ok anyway.
Here is a photo of the resin box. I chose this for the general size and the fact that it had a nice lip or edge near the top that would support the box if I built a frame around it.
This is look from the side.
Planter Frame:
The support for these floating guardrail deck planter boxes is very simple. It consists of a wood frame and two support brackets. I made the frame with 2×2 rough redwood pieces found in the garden department at Home Depot. They are pretty cheap at under $4 for a 8ft piece. Nice!
I cut the redwood pieces to make a box or frame with an opening to fit snug around the resin box ledge. Then I used #10 x 3″ exterior grade screws to connect the pieces together. it was quick and dirty. You could absolutely use pocket screws to hide the connections and spruce this up a bit. Here is the completed frame.
Note: this is a 3-sided frame! The deck guardrail acts as the 4th side. I didn’t want to add more pieces than needed, so I kept it was simple as I could think of.
Next, let’s connect this 3-piece frame to the deck guardrail with two small shelf brackets I also found at Home Depot on either side of the frame. Here is a side view to show you what I mean.
Disclaimer: this exact method works great because the top rail is flush with the side of the guardrail so the support brackets fit flush against the guardrail.
I used #6 x 1 5/8″ long exterior screws to connect the brackets to the guardrail. You only need to screw the top screws to keep the bracket from rotating away from the guardrail.
Here is a look at the floating planters from below.
Finishing Touches:
You can see in the photos that I made the support frame quick and dirty, but you could make these look even better with a little sanding, stain to match the deck, and maybe even some quick spray paint to the support brackets with either a brown match the deck or a black match the planter box, or whatever you like!
Project Costs:
Here is a breakdown of costs for each planter box
Resin Planter Box 7.86 in width x 23.75 in length: under $14
2x2x8ft redwood: Under $4/2 per box = under $2 per box
Small shelf bracket 5″x6″ = under $2/bracket x 2 per box = under $4
#10 x 3″ exterior screws: Use 2 per box. Let’s say $0.50 conservatively.
#6×1-5/8″ exterior screws: use 4 per box. Let say $0.50 conservatively.
Plants and soil can very largely depending on what you choose so we’ll leave that out here.
Total = $21 + tax. Most of the cost was the resin box! The fame a support was $7.
What do you think? I know I should clean mine up a bit, but these floating deck planter boxes add a nice touch of green to the deck without taking up deck space.
