I don't smoke myself, but I used to grow tobacco when I was younger. It was actually a big cash crop in my home town for the longest time.
Last year, I went back to my hometown for the first time in ages and the big tobacco fields, barns, and even the warehouses where they used to store the stuff before auction where gone. I only saw one crop of tobacco outside of town and the field it was in wasn't even that big.
Last I heard, it comes from Turkey now...
Sounds like Ross McElwee needs to make a sequel to Bright Leaves (2003)