Agronomic practices may cause cold damage prevention
There are actually several things that can be done. One is to control vine vigor, aiming for moderate cane size. Big, large diameter canes (called bull canes) that develop when there is excess vigor have buds with poor cold tolerance. Weak, thin canes have similar problems. Vine vigor is managed by "dialing in" the appropriate fertility levels and crop loading to match the variety, training practice, and site conditions.
It is also possible to drop some canes to the ground each year and hope that they will be snow covered during the coldest weather. Some growers put down canes and then actually bury them with soil. A lot of work to do and undo, but it really does assure bud survival. MSU Extension's new viticulture specialist in NW Michigan is planning projects to explore winter cold protection, he'd be agreat person to connect with. His email is firstname.lastname@example.org
Thank you so much for your time.
You are welcome.