In message , Janet Galpin
writes
I'm just beginning to hope I can plan a system of automatic watering
which involves different areas (greenhouse, polytunnel and pots on
concrete) all of which are fairly close together.

In order to get enough pressure to work sprinklers in all these areas,
I'm assuming that I need a few separate branches and time them to water
one after the other.


you might, it all depends on the area to be served and the system you
are using.

I presume that I would need a separate timer for each branch but can't
imagine how this will work if a timer is designed to attach to the tap.
Ideally I need to run a single hose extension for about 30 feet from the
tap and then have an arrangement which divides into four different
branches. Is there some kind of product which would achieve this and
take four different timers?


You can get splitters. to fit on taps, to supply different devices etc.
Though I mad made own from a few plumbing fittings, a little bit of
copper pipe and washing machine 'taps'

Another possibility would be to use the this device from Gardena:

http://www.twowests.co.uk/TwoWestsSite/product/COWD.htm

It automatically feeds different cicuits one after the other.


--
Chris French