It's invasive ... and the tree is too big for that spot, and dies back with every frost. it's the wrong plant for most of the valley.

Plant something better-mannered, like Palo blanco (Acacia Williardiana) or a desert willow.

dang, I really love the look of the Ficus and had my heart set on this. I need something evergreen to block night lights that shine into my bedroom window.

How about a Mastic tree (Pistacia lentiscus)? It is evergreen and small enough (15 x 20) for your yard. A fruitless olive (Swan Hill or Wilsonii) would be another suggestion.

You might also consider one of the large shrub/small tree options like Hopseed Bush (Dodonaea viscosa), Arizona Rosewood (Vauquelinia californica), or even Yellow Bells (Tecoma stans), Orange Bells (Tecoma hybrid) or Mexican Bird of Paradise (Caesalpinia mexicana).

Here is a link that might be useful: Landscape Plants for the Arizona Desert

Thanks for the suggestions. All the trees I like are just too big. I like the looks of the chinese pistache from photos.I'm from California and desert trees are still something I'm getting use too. I have a Palo Verde in the front yard, but I don't really want the desert look in the back.

Ficus, Oak and Elm are the trees I see most often that have the look I want.

Have you considered brazillian pepper? it's available at most nurseries, is evergreen and lush, does quite well in our climate. I am like you - I have the desert xeriscape in the front and want/have the lush oasis in the backyard... I would not go with any of the desert trees if you are looking for something lush green.... ficus is really a big gamble outside of central phoenix/tempe areas... it will not survive temps below 32F.... a few years back we had a devastating freeze which took out many of the ficus throughout the valley except in the warmer "core" of the city.... keep in mind that kind of a freeze happens maybe once in 50 to 100 years out there and you could go with a small ficus and be ok for decades... it's just a gamble.