Just out of curiosity, why would you choose this tree??? As one poster recently commented, asking about planting callery pears here (or in any nature-related forum) is like going on a healthcare forum and asking for recommendations on the best brand of cigarettes. Callery pears may not be a big problem in Arizona (yet?), but they are still among the poorest of choices for trees, IMO.

In Arizona it is probably very elevation dependant. You mention trees though so I guess you are not in the plains of Phoenix or something.

In St Louis they want full sun but actually seem better if grown in some shade as it promotes a thinner canopy.

Better yet, just don't plant it please.

I'm at 4500 ft in Zone 8a. Much cooler than Phoenix in summer and a moderately cold winter with snow. It was an apple-growing region a century ago..

Are you willing to hear other options for fall color? The Callery pears have become something of a scourge, escaping into areas where not welcome.

Do you know anything about your native soil type and pH? I'd really like to see this group of tree meisters help with alternatives for you than simply bash your choice. We're good at that, lol.

I already have Clevelands ready to plant. My only issue with them is properly locating them for adequate sun. I know their negatives but ornamental tree selections are very limited hereabouts. The flowering pears are a popular yard and screen tree in the region and yet have not naturalized; probably too dry for them without irrigation. And there are no other callory pears closeby with which to cross-pollinate.

"And there are no other call(e)ry pears close by with which to cross-pollinate."

Ya missed Jurassic Park, didn't ya? Seriously though, that doesn't seem to stop them.

If you are going to plant them anyway, plant in the most full-sun spot you can. They are full-sun plants.