Please see the message below from Dr. Sara Spayd, who is an extension viticulture specialist at NCSU. The information is probably more applicable to people in the southern VA, but we have not really seen cold temperature in the northern VA either. While we can enjoy outdoor activities in the middle of December, this warm weather is bit concerning for grapevines. Let's hope for a gradual temperature drop in the near future... -- Please pass this on to all grape growers: I know this beautiful weather is tempting, but please DO NOT PRUNE - even hedging. Pruning helps to stimulate vine growth. I would not be at all surprised if you see grape buds in some degree of bud swell, particularly the European bunch grape varieties. Those varieties have very little chilling requirement and it was likely met in the few cold days that we have had. The short predicted cooling pattern for this weekend will do little to harden the vines and buds for any potential cold...
Grape Disease Management Tips from Mizuho Nita (Grape Pathologist at Virginia Tech)