We can’t control Nature but we can learn from it. The last couple years have posed some real challenges for Northern Californian farmers, especially those who grow wine grapes. The extremely cool growing seasons of the past two vintages made it difficult to fully ripen the fruit before the potentially damaging fall rains came down. I wrote in more detail about the difficulties we faced in 2009 and 2010 and I’ll summarize by saying that coupled with the early onset and unusual heaviness of the rain, the seasons created a difficult choice for farmers: Either harvest the grapes before they are fully ripened to avoid the mold issues and dilution of the fruit that the rain could bring, or hope that the rain is brief so the ground dries and the grapes finish maturing. We like to say that these are winemaker’s years, when the great winemakers stand out. At Deerfield, we approached the vintage by making wines like those from regions of the world that never get too warm, like Bordeaux and Mosel Valley, and sorted our fruit even more meticulously than usual, sorting out moldy grapes caused by the rain. For a skilled winemaker, there need not be a bad vintage and ’09 and ’10 is proof of that, with outstanding wines like our 2009 Los Chamizal Chardonnay.
Well,  we’re having another unusually cool spring and it doesn’t yet have the  appearance of warming up, with the weather forecasting another week of  rain for the beginning of June. The farmers of wine grapes in Sonoma  County are quick to adapt however, seeing a recurring pattern. Last year  in an attempt to help ripen the grapes almost everyone in the Sonoma  Valley dropped some of their fruit from the vine, meaning they cut off  bunches of grapes that were good, curtailing the yield of each plant and  thereby channeling the vines’ nutrients and energy into the remaining  clusters. This year, some farmers I’ve spoken to, like Dan Sanchez of  Alpicella Vineyard, where we get our amazing Sangiovese grapes, say  they’re taking a more proactive approach by removing formative grape  clusters and reducing the yield before they even begin to flower. That  way the remaining bunches get the attention of the vine from the very  beginning.
The  current weather is helping growers make informed decisions about how to  approach the upcoming vintage. It also has more immediate impacts. In this episode of Cellar Rat TV produced before the last harvest, I talked about how our vines were  fortunately protected from the late spring rains. People often ask what  the effect all this rain is having on the vines. Water always means that  you could have a mold or mildew problem, which you can treat  organically by spraying the vines with sulfur. The more serious threat  is that the rain can damage the fruit set by hurting the nascent  flowers, either destroying them or washing away the pollen. The result  is loose bunches where only a few of the flowers were able to become  grapes, potentially diminishing the crop’s yield. On the positive side,  the increased rain means the water is going deeper into the soil and  lasting longer. This causes greater and deeper root growth, which will  produce a more vigorous vine the following year and therefore a bigger  crop.
The  wine-growing region of Northern California has incredibly diverse  climates, even in small geographical areas. While the rains might have  affected some of our neighbors in the Sonoma Valley where it is a little  warmer and the budding out therefore earlier, our vines are always a  bit behind in the growth cycle, probably due to the Kenwood Marsh  keeping the ground cool (I’ve noticed the closer to the pond you get,  the less developed the vines are). Our vines haven’t yet flowered and  the bunches are still protected by the little green pods called the calyptra,  so I don’t expect the rain will have any other impact other than to  make our vines grow vigorously throughout summer and perhaps provide a  bigger crop next year. Since the spring was cool and wet, we look forward to a long warm summer and late fall rains.