“The Vine that Struggles the Most Produces the Greatest Wine…”
This is a common adage heard around wine country, but what does it mean? In simplest terms, if the vine gets too much water and too many nutrients from the soil it causes the vine to put more energy into vegetative growth (such as the leaves and shoots) than into growing the fruit. This is why at certain times in the vine’s lifecycle, water stress is encouraged.
However, water stress is not wanted in the spring.
That’s because water is essential when the vines are first beginning to grow. Water stress at this time might prevent the initial growth that is required for the vine to continue development and produce fruit.
To help explain this a little more let’s talk about a vine’s composition.
Shoots are the structures that grow from the remaining wood left from the previous growing season. Shoot development is necessary for the early life of these vines because from the shoots grow the leaves, additional shoots, and inflorescences. The inflorescences are the flowers that will eventually become the grapes. Therefore, if water stress occurs at this time it would affect the shoots from developing and thus, the leaves and the grapes.
Leaves are required for photosynthesis to occur. Too little water will inhibit leaves from growing and maturing, preventing sufficient photosynthesis which can lead to a vine dying. That’s why adequate water is essential in the spring and even into early summer.
But this growing detail changes as we move later into summer.
Once grapes begin to ripen, this is when “the more the vine struggles, the greater the wine” comes into play. As mentioned previously, too much water at this stage will encourage more leaf growth rather than fruit development, thereby delaying ripening. It can also dilute the juice within the grapes, which would dilute the flavors and aromas in the grapes and therefore, in the wine.
Sonoma and Napa County rarely have an issue with too much water in the summer. In fact, some vineyards require irrigation because it gets too dry in the summer causing too great of stress on the vines. Some grape growers will choose to use what is referred to as regulated deficit irrigation (RDI), which means they control exactly when and how much water they will allow on each vine. Dry farming is also still practiced in many vineyards, which means irrigation is not used at any time.
As you can see, the timing and amount of water to produce the greatest quality grapes is a little more complicated than it might seem and is influenced by Mother Nature.