By Liz Thach, M.W.

I have a small hobby vineyard in Sonoma County with 90 pinot noir vines and 30 sauvignon blanc.  The vineyard is located in the Petaluma Gap region of the Sonoma Coast AVA which is a cooler climate ideal for pinot noir.  Every year it produces a nice crop with the pinot always ripening before the sauvignon blanc.  This autumn, however, when I walked down to check on the sugar level of the grapes, I was astounded to see that something had eaten 90% of the pinot noir crop.  The sauvignon blanc, which was still rather tart tasting, was untouched.

I called my neighbors with hobby vineyards to help me solve the problem.  “But you put up bird netting on the vines,” said Leslie, “so it can’t be birds.”  “You’ve placed yellow jacket traps all around the vineyards, so it can’t be yellow jackets,” mused Peter.  The whole vineyard is surrounded by deer fencing, so it couldn’t have been deer.  So what ate my pinot noir?

After a couple of weeks of looking for clues, I finally gave up and contacted the Sonoma County Winegrape Commission and requested their help in finding a viticulture consultant.  They suggested Laura who arrived a couple days later.  “Why didn’t you call me sooner?” she asked.  “Then we might have been able to see some fresh tracks.”  Then she ticked off possible suspects on her fingers:  birds, yellow jackets, deer, wild turkeys, raccoons, possum, skunks, or some type of insect.

I followed Laura around the vineyard while she searched for clues.  When the crime had occurred two weeks ago the weather had been hot and the vineyard soil was dry and dusty.  However, two days ago it rained quite hard in Sonoma County – right in the middle of harvest — so the soil was wet.

“So whatever it was didn’t eat your sauvignon blanc because it wasn’t ripe enough,” said Laura.  “Do you have any other grape varietals?”

Suddenly I remembered the two cordons of cabernet franc that didn’t successfully graft over when I had t-budded part of the vineyard last year.  For several years, I tried to grow cabernet franc but I could never get it ripe enough in the cooler Sonoma Coast climate.  So I grafted those vines to pinot noir, but a couple of them didn’t take.  Therefore, mixed in the pinot were still two cordons with long purple clusters – definitely different from the small tight pinot bunches of 777 clone.

Laura and I walked over to where the cabernet franc bunches had hung and I was astounded to see that something had eaten them in the past two days.  Laura bent down close to the vines and said “ah ha!”  She pointed at the black drip irrigation hose below the vines and there were tiny muddy footprints all along the hose where the culprits had placed their paws while eating my grapes.  Mystery solved – a very hungry family of raccoons had feasted on my vineyard.

Laura investigated the deer fencing and found two possible openings where the raccoons could have entered.  “They also could have just climbed over the fence,” said Laura, making me feel very helpless.  So the good news is the mystery of the missing pinot noir grapes has been solved, but the issue of how to protect my crop next year from raccoons is still a looming problem.  Any suggestions would be most welcome!