Each year the decision of when to prune is very important in any vineyard. It is even more important here in the Northeast, where weather patterns can be very varied from year to year. This past winter was one of the strangest that I have seen in many years. The past two winters were consumed with the Polar Vortex, where we worried about our grapevine's ability to withstand extremely cold temperatures. In these years, hybrids truly proved their worth over vinifera varieties. They survived with little vine and bud damage and produced abundant and healthy crops of grapes. The winter of 2015-2016 was a completely different story. It was a winter that could be more likened to Florida than New York. We had little to no snow and relatively mild temperatures. We had 70 oF in December! Really? My forsythia bushes actually bloomed. They were so confused. But so were most all my plants, including my grapevines. My grapevines' buds began to swell slightly in December. Being a bit of a worrywart, I was concerned, and I believe rightly so; what that would mean for the their production if we ended up having a typically very cold winter. Instead, we had one of the warmest in the Northeast's history.
So when to prune? Over the past few years I have typically pruned near the very end of March. The idea of pruning as late as possible in winter is to delay bud break. The reason to delay bud break is to combat the concern of a late frost. Once you prune and leave just about 10% of the vine for production that year, as you should, you end up accelerating the vine's desire to wake up. This year, however, the warmth continued; with record setting temperatures in many communities in the Hudson Valley. When I say record setting temperatures, I mean over 80 oF in early March! OK, for those of you that live down south, you're probably saying so what. For us here in the Northeast in trying to figure out how to handle our grapevines, we are scratching our heads.
With the strangely warm weather, bud break was imminent. Due to that fact, one needs to prune. If I were to continue to delay pruning any further, I would run the risk that the vines would have significant bud swell before pruning. Then, in the pruning and tying process, many of the then swollen and delicate buds could be damaged. This would then risk reduced production due to reduced buds. So what to do? Prune earlier than usual.