I’m very interested to know the result of the test.. do you use drip irrigation system, with adjustable drip emitters? If so maybe there’s a way to make the irrigation dripping a bit much at the group of plants that like much water and on the contrary on the plants that don’t like much water..sorry too theorical .. I haven’t chance to do this my self:)
I’ve visited some page about vertical gardening,
please see:
http://www.lushe.com.au/page/2/
dying plants on vertical garden is inevitable, and periodically, we have to switch the plants with the new ones.
one of drip irrigation tutorial:
http://www.irrigationtutorials.com/drip-emitter.htm
see month by month a vertical garden grow
http://verticalgardenmiami.blogspot.com/