I recently planted an English Ivy about 20 feet from this tree and read that the EI can cause bacterial leaf scorch in American Elms. Any thoughts on this? Do I have to worry about that in Phoenix, AZ? Also, what kind of tree is this?! How do you tell the difference?
Chinese Elm? American Elm?
I am not sure but It doesn't look like either Chinese or American to me. It might be Siberian Elm, I tree that I hate, but it is probably less thuggish in a drier environment than here in Ky.
On second thought, Ulmus Parviloia (Chinese Elm) is commonly planted in your area and the glossiness of the leaves matches that species. In my experience they develop lacey bark rather early. But since the growing conditions are obviously different here than in AZ, perhaps that will develop later there. Is the base of the trunk showing in lacebark characteristics? You might also have an American/Chinese hybrid. Since Chinese elm is resistant to Dutch Elm Disease, it has been used in hybridization to try to introduce that resistance into American hybrids.