I've always seen palmettos right on the beach in sand and other locations that were very dry so I always thought they just didn't need much water. In fact I tell people not to give them much water when they're planted since most people want to water them a lot to get them going. I guess I should rethink this. I do live in the deep south with usually plenty of rain and humidity up in the 80-90% range in the summer. Even durning the winter I think we run about 30-40% humidity.
I'm not much on palms but I think I may have to think about all this just in case.