Drive to your favourite hardware store and look for parts that you need to repair roof borders, a famous internet translation tool says me that the english word for this is 'verge flashing', the bented aluminum sheet part I used is called 'Ortblech' in german. And in profile view it looks like this:

  • measure the top of wall and cut aluminum profile with special scissors
  • cut four small angle profile (aluminum)
  • mark position of boreholes to join profiles via angle profiles and screw everything together
  • fill interior with EPDM foil
  • don't forget to cur hole in foil so water can flow out, dammed-up water kills your plants
  • fill up interior with foamed clay (3cm)
  • put flowe soil inside
  • spread your plants so it looks pretty, buy only plants that need a few water
  • don't forget to water your plants