This planter box which I made is a real space saver, as it hangs from the fence instead of taking up space on the ground.

By hanging it on your fence instead of the ground you accomplish two things:

1. The plants will get more sun, as they will be above other plants which might block the sun.

2. You will free up more space on the ground for other plants.

The only downside is that you will have to water the plants by hand as sprinklers likely won’t reach high enough.

The construction of the planter box is very simple, it is just a four sided box.  I won’t get into the construction but the dimensions of the box were 12 inches high by 16 inches deep by 24 inches wide.

The more complicated part was developing a system to hang the box to the fence.  To hang the planter I used shelving brackets.  The ones I used appeared very sturdy, so they should be able to support the weight of the planter and the dirt and plants which will be added.  Here is a picture of what the brackets look like, they can be found on Amazon here: https://www.amazon.com/gp/product/B01MTPRUGQ/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&th=1

I attached the brackets to the back of the planter box with nuts and screws, tightening the nuts as tight as possible.  I then screwed the bracket into the fence with one screw for each bracket.  At the end of the bracket I attached a block of wood which had a screw going through it to hold it in place. A nut at the end of the screw held the block of wood firmly in place.  The block of wood meets flush with the fence to hold the planter box firmly in place. 

I describe the planter box and the process to make it and hang it to the fence in more detail in the following video: