The word we keep referring to, with anything done in a vineyard or any step in wine production, is BALANCE. When it comes to the right amount of water/sunlight combination, balance is extremely important.
Late spring and early summer in Wisconsin brings out the most from mother nature. She likes to go on two to three day aggressions and bring anywhere from two to ten inches of rain at a time. The vines love all the rain so much they want to grow and grow and grow. When that happens the vines lose focus on the grapes and overgrowth occurs at the shoot level. This not only takes away the vines attention to the fruiting level, but it also blocks out the the sun’s access to the grapes, hindering adequate ripening, especially towards harvest time.
While overgrowth is not ideal for the perfect vintage, it is very manageable, especially when your consumers expect a consistent taste from the world-class wines you provide. When more than enough rain falls early in the growing season and overgrowth occurs, the next step is to cut back those overgrown shoots so the vines may refocus their energy. In a small vineyard (2 – 6 acres) this can be done by hand in a matter of a few days. On a commercial scale (7+ acres) an automated hedger is required to cut the shoots down and back towards the cordons.
This is the most important aspect when it comes to water/sunlight balance. It is imperative for any vineyard of any size anywhere in the world, to maintain adequate growth. This means the vineyard manager or winemaker MUST inspect the vines on a daily basis to react to what the climate has done. Balance.