Do Vines Care How Long The Winter Is?
The question has been posed to us: do vines care if the winter is short or long? This is a tricky one. First, on a fundamental level, this is a deeply philosophical and ethical question. To care is to have consciousness. Do vines have consciousness? A plant lover might say yes. Or do just some vines have consciousness? Do burgundy vines have consciousness while Bordeaux vines are just dead stupid? Our role here is not to inflame the passions of an already divided country, so we’ll just take a pass on that entire angle.
The more pertinent question for us wine lovers might be whether we care if the winter is long or short. There is one easy answer: yes, of course! If we had an extremely late bud break followed by an extremely early harvest, the growing days would be limited as would be the maturation of the fruit. Of course, that’s never the whole story. The daytime and nighttime temperatures during those growing days play a role as does rainfall. So you can’t completely judge by just growing days. But in general, shorter growing season = less developed wines.
But even here we cannot be categorical since that growing season might lead to brighter, more acidic and lower alcohol wines that are prized by many Pinot drinkers.
Still, we can say that a growing season of zero days (we call this the Day After Tomorrow scenario) would be bad, as would be a 365-day summer (we call this the new reality scenario).
Winter snow at Saffron Fields Vineyard, Yamhill, Willamette Valley, Oregon
But seriously, within a normal range with the vines dropping their canopy in mid to late October and bud break in April or May, how much do we care about the sleeping time of the vine? In the more-than-you-needed-to-know to know category, there are actually two phases of sleeping for vines: endodormancy and ecodormancy. The first stage, endodormancy is triggered by shorter days and cooler temperatures. During this time, the vines are preparing themselves for colder winter temperatures. This phase starts well before leaf fall. To go back to our Day After Tomorrow scenario (for those confused about this reference, in the 2004 movie, climate disruption in the Atlantic currents causes North America to turn into a large ice cube), an extremely early freeze could disrupt the normal cycle and the vine’s preparation for colder winters. In any event, during this phase, a certain amount of cold temperatures is necessary to prepare the vines for the following spring’s bud break. In other words, unusually warm temperatures in late fall and early winter can disrupt spring bud break.
In the second phase, ecodormancy, vines are ready to grow, but the cold keeps them from doing so. At this stage, both growth and bud break can be stimulated by warm temperatures. Once growth has started, there are no takebacks. This can be a bad situation. Think back to 2022 when an early bud break was followed by a late frost. Those early buds were devastated and initially there was fear that the entire 2022 vintage would be lost in some vineyards. Fortunately, secondary growth was surprisingly robust, averting financial disaster for vineyards, or at least for their crop insurers.
So the bottom line is that what we want is a winter that sets in at an appropriate date and has persistently cool or cold temperatures. An early spring, while delightful for us, poses danger to the vines if it is followed by the resurgence of cold winter weather. And no, turning North America into an ice cube would not be good for the vintage.