Thanks for the tip. I'm always amazed at how well Bougainvilla grow,
seemingly unattended, along highways around Phoenix. The ones in my
yard don't do nearly as well, and I've suspected for a long time that
car exhaust gases :-) seems to have some kind of beneficial effect on
the plants.

That said, I've tried years when I didn't water my ground-planted B's
at all - and other years when I've been more aggressive - I personally
haven't witnessed that "water-starved" B's do better (more flowers or
brachts), but I've read it many, many places.

By the way, thanks for your very valuable hyperlink to your B site!!!
Lots of interesting material I will digest there!!