Your little roof is gr8. U don't want too much weight on there though.....
Am always amazed at how much people can grow in tiny spaces.
Have either of u tried herbs? Med ones would do well.
Thanks - good point about the weight, but it's a sturdily built block, and all our pots are quite small - no huge heavy planters.
Lots of herbs - parsley, sage, rosemary and thyme, also mint, bay, chives, basil.