Fertilizer for Mediterranean aromatic plants ?

[JimFit]

Hello, i am planning to build a vertical green wall with oregano, thyme and some local flowers, i was wondering how soon i should give them fertizilizer
given the fact that they won't have much soil, also what system is the cheapest to automate the process? Thanks

 

[Marck]

I would apply some fertilizer at time of planting and then continue on a set schedule going forward. Depending on the plant and the climate you may make seasonal adjustments.
There are many designs and methods for building and maintaining a 'green wall'. I'm not certain which processes you wish to automate cheaply.