A couple of years ago, I went to New York City to visit my newborn grandson Daniel. Holding him in my arms, I couldn’t help but marvel at how that tiny little thing would one day grow into a man. I tried hard to remember all the developmental stages he would be going through to reach adulthood. It’s nothing short of a miracle.
Like a human, a grapevine undergoes many biological milestones during its maturation. And it’s a process that repeats annually. Plant scientists have a term for that — phenology. Derived from the Greek words of “phainō,” meaning appearance and “logos,” meaning knowledge, grapevine phenology is the study of biological events in the vine’s annual life cycle as influenced by climate and habitat.
To help me understand better the phenology of grapevines, I enlisted the help of Cameron Hosmer, the founder and owner of Hosmer Winery in Seneca County. He has been growing grapes in the Finger Lakes since 1980 and has some of the oldest vinifera vines planted in the region.
My plan was to track a single riesling vine in Hosmer’s vineyard for one year. I began my visits in May of last year, during bud break.
May 18, 2020
May is an exciting time for Finger Lakes vineyards, as bud break typically occurs during this month. It’s the time when the hibernating vines wake up and burst forth with green shoots. It’s akin to the birth of a child, full of hope and promise for a new vintage.
On a cool and cloudy day, I met up with Hosmer at his winery. He is a hearty man with a ruddy face colored by years of working outdoors. Bud break had already happened through most of his vineyard, but his rieslings were just beginning to bust out.
“Riesling is one of the late bud break grapes, and it’s probably happening a little later than usual this year,” Hosmer said. A cool early spring had slowed down the vines’ natural process of preparing for the new growth year.
Over a typical winter, grapevines go through a process called cold acclimation. They do so by self-dehydration: A self-imposed drastic reduction of internal water so ice crystals don’t form to wreak havoc on the plant tissues. At the same time, a brown exterior protective layer of cells called periderm is grown to insulate the shoots from the harsh winter conditions. Other chemical changes in the vines such as the accumulation of sugar help them withstand cold temperatures as they lay dormant.
Beckoned by longer days and warmer temperatures in the spring, the vines reverse the process and plant growth resumes. “For bud break to happen, the temperature has to stay above 50 at night. You get a few nights like that, and all of a sudden, bud break happens,” explained Hosmer.
But bud break also represents a nervous time for cool-climate growers such as Hosmer in the Finger Lakes. As the vines shed their protective winter coats, the fragile buds become vulnerable to frost and cold temperatures.
“Last week, the danger of frost was very imminent when the temperature dropped to 28 overnight. Luckily, we dodged a bullet,” he said. “We should be okay now. Usually by May 15, the danger of frost is past.”
But a few vineyards weren’t so lucky. One lost pretty much its entire 2020 crop due to that early spring frost event.
Hosmer and I walked onto his estate Patrician Verona vineyard. We selected a vine on a riesling plot — the first one on row 18. The buds on this vine were just about ready to burst out in green shoots. There was a sense of spring optimism in the air, as the vineyard had awakened from its brown winter torpor and was now starting to sport a verdant sheen.
Yet, many perils still were ahead, with weather events being just one of them. Insects, birds, fungi and other disease pressures would test the mettle of the vines and the vintners time and time again throughout the growing season. We were only at the starting gate.
Hosmer gently reminded me of that with these parting words of wisdom, “Remember, we are not in charge.”