The answer to that is — I don’t know — yet.  The damage to vines from the extreme cold temperatures we observed around the state (-19 F Stillwater, -13 F Perkins, -15 F Chandler, -10 F El Reno, -31 F Nowata(!), etc) won’t show up for a few days.  We need some of the warm temperatures to make the vine manifest the damage symptoms.  One saving grace is the snow that acted as an insulator, so if vines were damaged or killed above the snowline, then below that they may be o.k.  This is how many vines survive in the more northern regions of the country.

But, what do we know, research-wise, about cold hardiness.  Not enough, but studies by Dr. Tony Wolf in Virginia have shown hardiness of vinifera vines to be about -8 F.  That, of course, is dependent upon the cultivar, the health of the vine, the time of the year, the weather preceding the cold event, etc.  Is something like Syrah going to be cold hardy to -8 F?  I don’t believe so.  Cabernet Franc?  Probably.  How about -19 F?  Good luck with that.  It will be very interesting to see what happens in the next couple of weeks.  This is certainly a real “test” winter so far.

Anyone out there who would like to share their damage observations I would love to hear them.  In 2007 I wrote a report after the April freeze.  If I have enough data I will do the same for the 2011 Deep Freeze.