The vitex can get very big. There is one on 51st Ave 1 block north of Peoria on the east side of the street, corner lot...SEC. Very mature. Huge.
The two mesquites in my backyard are Chilean. Planted in the fall of 2008. Love 'em. Full sun for both trees, vitex and mesquite.
http://ag.arizona.edu/pima/gar...
How fast is fast? If it grows too fast Kelly, the underlying structure is weak. Old Chinese saying....best time to plant tree, 20 years ago, next best time - today.