What kinds of regulations are there on home-grown tobacco?

Apparently, none:

“As a result of federal legislation in late 2005, restrictions of commercial tobacco production to quota holders are no longer in effect.” (see here)

I’m not sure about growing your own for private use (although it seems, to the uninformed mind, that you’d be okay), but when you start selling things like that, the government is sure to want their cut. That’s why we have the Bureau of Alcohol, Tobacco and Firearms (and Explosives).

The most current information I can find about taxation on tobacco products is here. When the Man doesn’t get his money, he can get all in your face about it in a severe way, so it may not pay to fight city hall on this one.