Jefferson has been very vigorous for me in NE Ohio. I planted one three years ago, had near total die back after the first of two brutal winters, but it survived and put on nearly 7’ of growth that summer. After last year’s equally brutal winter it was perfectly fine and I got one fruit this summer. Very tasty. I planted two more this spring and they both put on quit a bit of strong growth as well. I have black knot problems and have only noticed one tiny 1/4" knot so far on any of the Jeffersons. Most of my other young Euros have much more, even a Kenmore had some.