What is a cold hardy grape? A cold hardy grape has been bred to withstand cooler winters. In our area this can frequently be somewhere near -30 F. Without special labor intensive protection, the traditional varieties like chardonnay and merlot, simply would not survive here. With decades of work done by private hybridizers such as Elmer Swenson and University of Minnesota Agriculture programs, we now have several grape varieties that survive the cold winters and produce great wines.