vintner may 1

The Vintner’s Calendar: May

Sebastiani Winery in Sonoma, California has historic wood carvings on display on their property, including an intricate depiction of the winemaking calendar. Each month is represented separately with a special part of the process a winery participates in to yield great wine.

Throughout the year, we ask winemakers to explain what’s happening behind the scenes each month as part of our The Vintner’s Calendar series.


With vines starting to grow and the anticipation of bloom around the corner, May is an exciting month in the vineyard…but it does come with a little worry. At this point in their lifecycle, vines are very fragile and susceptible to frost. If the new growth is hit with freezing or below freezing temperatures it will severely damage the vine, with the effects lasting for up to two years!

The most important thing vineyards can do to combat the frost season is prepare. Most have preventative measures ready; a traditional method is the use of smudge pots, which can be placed around the vineyard and lit with diesel to increase the vineyard’s micro-temperature. Due to its climatic impact, we’re seeing this being phased out in favor of more eco-friendly alternatives. More popular in New World wine regions is the use of large fans in the vineyard, which are used to circulate cold, low-laying air.

Alicia Sylvester, who spent time as Assistant Winemaker at Lancaster Estate before moving over the the Winemaker role at Merus, explains that the impact of frost is different for every winery.

“Luckily, Alexander Valley is one of the warmer California American Viticulture Areas so we have a lower risk of frost in total. Lancaster’s topography and gentle hillsides are also natural frost preventers. There are less low laying, valley floor vines, where cold air may lay and freeze our new growth.”

No matter which approach a winery decides to take, combating frost and other elements that come their way during the month of May will ensure keeping the vines healthy and fruitful for years to come.

Catch up on the other installments of “The Vintner’s Calendar” here.

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