Hi
I have a Canadice seedless grape vine and a Stueben vine (like concord)
planted side by side.

The first year I got grapes from the Canadice they were seedless as they
should be.
Then, we had 2 bad winters where both vines died right back to the ground.
This year, I got about 6 clusters off the Canadice and some grapes had
seeds. Some seeds were very small but some were normal size.

The local nursery says that it shouldn't happen but I think some cross
pollination is going on or the Canadice is a plant grafted onto a base plant
which does have seeds and after the die back I'm getting branches and grapes
from the base plant.

Anyone know what's happening?

Tnx
Wayne