The wall made of glass in the second picture has either a soil based background, with the soil kept in place by a net, or has a hydroponic system that flows the nutrients through various pipes located on the back of the wall. I suspect it is the latter. Either way, the plants need to be fertilized on a regular basis.
Your can add soil to the other side of your wall and anchor it with plastic net, but only if the wall has holes that the plants can use to cross to the backside, otherwise vegetables won't have enough nutrients to flower or set fruit, not to mention the risk of rain washing everything off.
Plants that you can grow in the small cracks include Hedera and some rock-loving groundcovers hardy to your zone. Also, there are a few succulents hardy to zone 3 and 4, like some species in the genera Sedum and Sempervivum. These plants don'r require fertilizing and may be planted each on every crack.