Planter boxes from old shelves

We have a small plot on our flat roof to grow our greens and since it's a terrace, we have to grow in containers.

The previous owners have done a fantastic job on it and left us a few nice plants. But of course we want to grow more and have planned this even before we moved by keeping some of our old shelving units to make into planter boxes. 

Our old shelves in pieces

I have resisted buying any additional pots or grow bags until the planters are made, to ensure I don't buy anything unnecessary.

Finally we had some time to get started and this is what we have made so far. 

First planter box