First time making a flower box.
I decided to make a large flower box for the side of my shed while waiting for parts to be delivered for my log burner.
I used unbanded scaffolding boards to make the flower box. The dimensions are 2.6 metres long, 225 mm in width and depth, and the plank thickness is 40 mm. I treated the box with a creosote substitute both inside and out. For the base of the box, I used a UPVC fascia board. Then I stapled plastic sheeting to the inside to protect the wood.