Q.Is Purple Fountain Grass invasive
I live along the Colorado River in AZ and have been told that Purple Fountain Grass is invasive and should not be planted here. After looking into this further it appears some species may be sterile. I’m wanting to figure out which I have.

Thank you!

Unfortunately, all varities of fountain grass should be considered potetially invasive.
https://www.unce.unr.edu/publications/files/nr/2002/FS0250.pdf
"While the nursery varieties are said to be sterile, there is no clear evidence that they will not add to the spread of fountaingrass. Several varieties of Pennisetum setaceum may be sold, ranging in color from reddish to rose or purple. All cultivars are considered invasive and should not be sold or planted."
Too bad, because its beautiful. Don