I planted 6 Concords this spring (my first Concords) and they are doing good. I have them trained to the top condon and along the top wire as far as I want them to go and I snip the end so that it can start on cane growth. So my question is, are Concord vines considered vigorous? I accustomed to growing other vigorous vines (America, Buffalo, Sheridan) and the America vines I planted at the same time as the Concords have already have both top cordons and have numerous canes. The Concords are not starting canes and I see no sign of a bud to use as a second top cordon. All of the primary leaves look healthy with little sign of disease. Are they spending their energy on root growth? I must say they seem very resistant to downy and powdery mildew as with the America vines it's a constant battle. Any input is appreciated.