Great idea... I know a lot of people on the Arizona forum have suggested the Phoenix zoo for their Plumeria display (although it is the last place on earth you'd think to find them...)

If you're ever in Tucson, The Sonoran Desert Museum is both botanical and zoological, with a great Hummingbird house, geologic and reptilian displays and some great info - a must see.

I have been to the Phoenix zoo three times and it is great landscaping there. I have seen Sonoran Desert Museum two times and there is a botanical garden outside of Phoenix, maybe 40 miles or so, and that is great to walk through. Going up the hills can be taxing in the heat but I am still able to make it if I go slowly.