Q.I am told to cut pampas grass back in late winter,
I live in North Florida, (Tallahassee), our winters are typically mild, when would you suggest? Thank you

This is as much a matter of convenience and personal preference than what is best for the plant. Some people like the look of the pampas grass even when dried out and tan colored. Other people are "done" with it for the season and ready to cut it down in late fall. Of course, you can enjoy the pampas indoors as a dried flower. Whether fall or spring, the important thing is to cut it down before new growth starts in spring.