Trevor, my philosophy is based on using water in holes at time of planting in my seven year old garden in Central Otago, NZ, and none after that. I do water my vegetable garden,and also young trees to establish.If plants die I don't replace but look for another more successful candidate. I am stunned by just how many great plants will not only survive but thrive without water here.
My rainfall can go as low as 288mm in a dry year, and in this last week (early summer) we have had 2 days over 30 degrees C. It rained today for the first time for 28 days. February is usually the hottest month so the summer is just starting. Not as extreme as many Australian sites, but the driest and hottest spot in NZ.