Ask Mr. Smarty Plants

For openers, our Native Plant Database lists Fraxinus texensis (Texas ash) as being native only to a strip down the center of Texas and a small part of Oklahoma. We understand it is rare in the trade. Sometimes trade names are used that do not match up with the common name usually accepted for a plant, so  it may be that your tree is either some other ash or is a hybrid, which means it will not appear in our database.

Another possibility is that you have a cultivar of Fraxinus velutina (Arizona ash) with the trade name of Fan-Tex. Here is a previous Mr. Smarty Plants answer that will give you some information on that. This USDA Plant Profile Map shows the Arizona Ash does, indeed grow in Maricopa County, while this map on Fraxinus texensis (Texas ash) does not show it growing in Arizona at all.

There are so many things that can cause ash leaves to exhibit the symptoms that you list, we are going to refer you to a website from Iowa State University Common Problems of Ash Trees that has pictures and descriptions. Once you have read that, we suggest you contact the University of Arizona Extension Office for Maricopa County. Regardless of which ash tree you have, if others are having the same problem the people in the Extension Office should know about it.