On Tue, 6 Sep 2011 16:52:40 +0000 (UTC), eternal vigilance
wrote:

I have a very long line of rhododendron bushes which are hardy but are
starting to wilt.

" hundreds of yards " of tubing?

I noticed the animals chewed right through the thin plastic in just a
couple of spots.

A landscape nursery will have a number of ways to make repairs. One is
cut the line an put a coupling on the tube. It slips over the cut
tubing.

I can't for the life of me, find where the water comes from that feeds
this irrigation line (it has always been dry since I bought the place
from the bank, owner unknown to me).

Keep looking.

To get a background on this thin piping, what is an accepted repair
procedure?


So many possibilities... How deep is the poly buried? Where are you
located? The 1/2" poly can only last so long as it weakens, cracks,,
splits and all the above. Sometimes, it is better (cheaper) to pull it
out and replace with new. Fix one leak and another one starts.

And, normally, how does it get it's water? I find no sprinkler electrical
box that feeds this line???

You might try pulling some tube up (if just below the surface) closest
to the house and follow the line that way.

http://www.starnursery.com/irrigation.html

YMMV