A Mild Winter: Good for Grapes?

Friday, March 9

Many people (and I mean MANY) have asked me, “How is this mild snowless winter treating your vines?".  The simple answer is “Right now, the vines love it!” After all, vines growing in most of the world typically see winters like this. But I tell people I am worried about what might happen this spring. I’ll explain later.

First, let me explain how a vine endures winter. In fall the buds formed during the previous growing season produce a robust layer of carbohydrates to protect them during dormancy. Each bud contains the flowers of next season’s fruit. Typical European varieties such as Chardonnay, Riesling and Cabernet will sustain serious bud damage when temperatures fall below the -10 ْ F range.

 

Our 15 acres of grapes are mostly hybrids, botanical crosses of native American grapes with European varieties. Hybrids are both hardy and good wine producers. The latest hybrids we planted, like Marquette and La Crescent, originated in Minnesota and their dormant buds can survive winters of 30ْ below! This season’s low of -3ْ ْF means even our tenderest varieties, like our Riesling and Vidal, are in good shape going into spring.

 

So why worry? Well, the Minnesota  hybridizers thought they fooled nature, but these super- hardy varieties turn out to be the earliest to bud in spring. Bud break happens late in April here.....normally!  But… with current mild weather patterns it could happen earlier in April and once it does, even the cold-hardiest vines are on equal footing with the least hardy. Once the shoots reach a half inch or so in length they are vulnerable to a sudden spring frost.

They can likely sustain 32 ْF, but will be severely damaged at 28ْ, killing all chances for fruit in the coming season. The vines will survive and likely recover the season after.....but that's a long time to wait for fruit. It used to stay cold long enough to avoid vines being “ nipped in the bud.” But this year we’ll worry until we get past May 10th.  So stop by for a glass of wine and toast with us to a traditional VT spring.  ~Ken