A Year in the Life of Cabernet Sauvignon: Winter

Each year around the end of November, the California temperatures begin to drop, and the last leaves fall from the grapevines. Autumn reds and oranges slowly slip into the distance and we welcome a new season: Winter.

While the winter season in the Napa Valley is milder than in other parts of the country, our proximity to the San Pablo Bay leads to dense ocean fog rolling in on a daily occurrence. This in turn, leads to extreme temperature fluctuations with nighttime temperatures often dipping near or below freezing. Cold temperatures are what send the grapevines into their final stage in the growth cycle, and consequently where the next year’s growth cycle will also begin.

In 2021, we invite you to join us in following the journey of the Cabernet Sauvignon vines at our beloved Winston Hill Vineyard. Our blog will be updated as the seasons change, and we hope that you will check back often to see how the year and the vines progress.

Pre-pruned dormant Cabernet Sauvignon vines at Winston Hill Block 5 – February 9, 2021

Late November – Early March: Dormancy

Dormancy is a sort of defense mechanism for the grapevine. This deep winter slumber is a way for the vine to rest, preserve energy, and protect itself from the harsh cold and potential frost that may come throughout the winter months. No vine growth will occur during this time. However, it is important for our vineyard crew to monitor daily temperatures because an unusual heat spike could lead to a shortened dormancy period, which could influence crop yield come the next fall’s harvest. Ideally temperatures will stay cold enough to keep the vines dormant until the Spring. At our Winston Hill Vineyard, dormancy typically ends around early March.

Mustard cover crop at our Benjamin Vineyard in Rutherford – February 23, 2021

While the vines are sleeping, other plants make their presence known in the vineyard. These cover crops are here to replenish nutrients in the soil that have been depleted by vines throughout the growing season. At Winston Hill, we practice a no-till program, which allows native, volunteer cover crops to flourish from January through March.

Mid-to-Late February: Winter Pruning

A few weeks before the end of dormancy in mid-to-late February, Winemaker Todd Graff and our dedicated vineyard crew, are keeping a close eye on the weather, aiming for a day with sunshine and no rain in the forecast. When the timing is right, a special, ritual-like farming practice occurs: the art of pruning.

Pruning is the process of removing the previous season’s vine growth in order to prepare the vines for the upcoming growing season. In the Cabernet Sauvignon vineyards at Winston Hill, our expertly trained vineyard crews meticulously walk the hillside rows, hand-cutting each cane. They aim to leave less canes on weaker vines and more canes on the stronger vines, which will create vine balance as the vines begin to grow throughout the upcoming season. The crew is also careful to make intentional cuts far enough above the woody part of the cane whenever possible. This method protects sap flow within the vine ensuring nutrients can freely flow to new fruit that will grow later in the season.

We’re only a few weeks away from the first signs of Cabernet Sauvignon growth, marking the start of the 2021 vintage! Follow @frankfamilyvineyards on social media to see the vineyard growth cycle in real time!