Check out this map. BB has been reported as invasive in Wisconsin. But the red blur on the East Coast is where they were planted, a lot of them, 150 years ago. It's time to stop planting them, or most of the country will be a red blur! You may keep yours, but don't give any away to friends! ^_^
Thanks for reading and letting me know -- it's been very interesting getting reports from all over the country.