I transplanted a 4-5 year old grape vine (Concord type) last November. It sat there over the entire winter and spring. When I put down the shovel and going to dig it out last week, I found a lot of white hair of roots. Today, I just saw a tiny bud popping out a few inches above ground. The main trunk is about index finger thick.
I do not know what made this thing dormant this long.