Bigyin wrote on Mar 30^th, 2016 at 7:35pm:

This isn't the brown perforated hose that Colin is talking about and these little goteras and the tubing can be bought locally.  What head of water are you feeding these with Maxwell ?

Thanks Bigyin for pointing out all the various posts on this thread have not addressed my original question. 

Did I need a lecture about choosing plants that don't need watering? No. 

Have we spent a lot of time and money preparing a long trench for an olliander hedge?  Yes. 

Shall we water the new plants or let them die?  Believe me, not even 6cms of rain in 36 hrs is going to keep young plants going for long.  The system we have now installed allows us to decide what plants we want and where, it's cost effective and reliable, using timers and selective stopcocks .....  and doesn't rely on sparse rainfall we experience.