On 24/06/2014 10:16, wrote:
There are also gadgets to turn the water on when required, some even attempt to compensate for rainfall, or measure soil moistu
http://www.hozelock.com/watering/aut...er-timers.html
http://www.greenhousesensation.co.uk...ter-timer.html
http://www.gardena.com/uk/water-mana...ater-controls/

There are a number of rapsberry-pi based systems. I can't find it now,
but someone in the US does a commercial one which looks like a little
gun - tilt, swivel, aim, squirt. Apparently you can program it to water
each plant individually...

Andy