Dr. Dave Miller Michigan Wine Blog
As I write this blog I’m looking out the window at a beautiful day, temperatures in the mid 60’s and the forecast is for mid 70’s for the next week. Awesome! I love warm weather and spring as much as anyone and I can hardly wait to get outside and sip a glass of wine on the deck. We are coming off one of the mildest winters in memory (and on record) and now this – spring in the middle of March. So is it all as good as it seems? What does this do to grapevines?
Since we really never had a deep, prolonged freeze this winter the ground never froze solid. Without frozen ground, overwintering plants, like grapevines, start to respond to warm temperatures sometime around the end of January. As plants respond to warmth they come out of their deep, winter dormancy and start getting ready to grow. I observed soft maple trees, which typically bloom around the middle of March, blooming in February this year! Overwintering animals respond to the conditions too. I saw my first Robins in February and the Bluebirds were looking for nesting boxes the second week in March. Maples were tapped in late February too. All of this means that spring is here early and there is no turning back. It’s a great cure for cabin fever but it gives pause to those of us in Agriculture. Why? Our biggest concern is frost. With May 10th the average date for our last frost in this region we have 6 to 8 weeks before we are out of the woods. The vines have not started growing yet but my guess is we’ll see bud burst in early to mid-April, 2 to 3 weeks ahead of average giving us several weeks of frost danger. When the shoots have started growing and get frosted the crop is reduced, the magnitude depends on the severity of the frost.
Now that you all can imagine Jack Frost taking our grapes this year, let me give you the counter – point. An early spring means an early start to the growing season. Some of our best and longest seasons started very much like 2012. A long season means the grapes begin ripening earlier and have longer to hang and mature. That leads to some awesome wines, especially late season reds that need the extra heat to fully mature. Also, the mild winter means there is little to no winter injury in our vines. With no winter injury all of the buds produce shoots with fruit and the stage is set for a big crop. So if we dodge the frost – bullet this spring we are in for a big crop with plenty of time to ripen and lots of great wine. As much as I want to know how it turns out, experience suggests I sip my glass of wine on the deck and enjoy the ride. Time will tell how the story ends. In the meantime we should savor the fruits of our labors from last year. So let’s enjoy the next week of mid 70’s with a glass of our favorite spring-time wine. Pinot grigio or Riesling anyone?
Dr. Dave Miller
14 March 2012