I know that Phoenix is really warm in the winter time, I live about 3 hours away in Safford. Have you given consideration to just planting them in the ground? I don't think it gets colder than 40, right?

Jordan - Yes it is pretty warm here but we do get below 40 in the winter. I have 4 planted but wanted to leave the rest in the pots to I can easily move them when needed. We wound up building a 2' fence/screen wall to hide the planters. Thanks for all of the input from you both.

you can build your planter and then plunge your pots filling the planter with soil mix. If you take your pots inside for the winter, you can drill many holes into the pots. Roots will grow out of the holes into the extra soil. At the end of the season, cut around the pot with a knife and remove the pot for storage or root prune inside the pot. Throw the old soil out with the chopped off roots and replace next season. Just an idea.

I use a comparable method to what Bill posted above.

No, the black nursery pots are not good for places like AZ and TX because the roots will cook in them over summer, unless you plunge as suggested by Bill. This is really easy to do, and makes life much easier when you need to get them in before a freeze. A big planter box sounds ideal!