They’re not native to New England. Long Island and far SW CT is debatable, but i don’t think they are there either. The generally accepted northern range is pretty much what that map depicts…spotty native areas near water in IA/WI near the MS River and then hugging the southern Great Lakes into S MI, S ON, and far W NY. There’s people successfully growing them in MN, VT, NH, and QB now. They’re pretty cold hardy…well down into the -20s. What limits their range is the length of growing season not being conducive for propagation.