I have been to the Scottsdale area and there are lush golf course, tree lined steets, etc. Some people will landscape their homes with gravel, and catus but it's not a requirement.
In fact I heard that there are neighborhoods in Phoenix that require that you plant and maintain a lawn in front of your hous, or at least some portion of your front yard must be grass.
As with most hot dry climates, trees do not grow very tall (except palm trees) but some varieties of trees do grow well, especially if watered regularly. The only drawback to having greenery in the desert areas is a lack of natural rain water, so you must provide some form of irrigation, and water may be a bit pricey.
...Rich