Below you will find our flower box selection to add a touch of class to your storage shed, outdoor building, barn or playhouse. They are available in 18″ width and 24″ wide versions. Boxes are made of durable polyethylene plastic and come in several colors. Unlike wood flower boxes, these are made of plastic and will not rot, warp, fade, or get destroyed from the outside elements. All you need to do is add some flowers!