I'm pretty sure that a poster on this forum was from Arizona and use to make pots. I got a lot of hits when I did a search on this web site. I've attached a link from someone on the Arizona Gardening Forum that makes hypertufa.

Don't know if it's still available but you use to be able to have your state or gardening zone next to your name. If it is, I hope everyone that reads this will add that information. It helps when you are giving/receiving help. I've been making hypertufa for a long time and have my pieces in a lot of different garden zones. The "expert" would be someone in your growing zone.

http://forums.gardenweb.com/discussions/1731246/made-some-hypertufa-pots-what-about-you