Along the Upper Lewes Road we have walls which regularly get painted with tags and worse. Then the Council sends its gateway graffitti squad to paint it out, to keep our visitors happy. This is a waste of time and money.
When visiting Beverley in East Yorkshire recently I saw that many homes fronting the street had planted cotoneaster in holes through the pavement, and trained the plants up their walls.
Walls in Brighton could be similarly enhanced and protected. Guerilla Gardeners get out there and just do it.