Jeff’s Corner 5-6-22

Not too long ago (Jeff’s Corner 4-1-22), we began a series on the critical stages in the life cycle of a grapevine. We talked about the vines coming out of dormancy and springing back to life with “bud break.”

When flowering begins, the buds produce clusters of flowers (called inflorescences) which will later become our grape clusters. In these really cool photos taken by my colleague and friend Chelsea Scott, you can see the early stages of flowering in our Montepulciano vines.

Grapevines are “hermaphrodites,” meaning one plant is both male and female. Since they fertilize themselves, there is no need for bees or other pollinators, and they produce what are referred to as “perfect flowers.”

The inflorescences are covered with a cap of petals called the calyptra that exposes both the stamen (male) and the pistil (female.) Fertilization occurs when male pollen from the stamen adheres to the sticky surface of the pistil, which is called the stigma. In about two weeks fruit set will occur and we’ll have have a cluster of tiny grapes that will soon become wine.

Like bud break, this is a critical stage in the vines life cycle. Not all the flowers will pollinate, and those that don’t fall off the cluster. This is called “shatter,” and plays a big part in the vines’ ultimate yield. Shatter is how the cluster prunes itself to control its yield, however high winds, hail, and heavy rain can cause too much shatter and the yield becomes less than desired.

We’ll see you in a few weeks and talk about “fruit set,” the next important stage in our journey from bud break to bottle. Please feel free with questions and comments, and if I don’t know an answer I’ll go to the source, our outstanding vineyard manager, Clint Messimer.

Thanks for reading, everyone…