Vineyard Update | Early Frost
Mother Nature reasserted her command of events with 27 degree nights on both April 6th and 10th. Normally this would not have presented a problem as the buds on our vines would have not yet broken dormancy. Normally bud break occurs in mid-April; but normal seems to be a word being purged from the Virginia weather lexicon. After a mild winter with some very warm days, bud break came in the last week of March, two weeks early. Two inches of tender green new growth was exposed to the freezing temps.
A Call to Arms
Late in the day with a beautiful blue 50 degree cloudless sky we were finishing up in the tasting room when we heard the helicopter approach about half of a mile out. I asked Carlisle (partner and chef) if he wanted to take a spin. “Hell yeah” he said. I responded: “If we’re gonna get our ass handed to us we might as well get a ride and some pics out of it!” We got to the landing zone as the helo was setting down. With the blades at a high rpm to allow us to approach the aircraft, we hustled out and climbed in. With headsets on so we could speak to the pilot and each other we took a lap around the two vineyard blocks, the winery, and Upper Shirley proper. The view was spectacular.
After dinner I tried to get a nap in. My racing mind would have none of that. At 9pm I made my way out to the vineyard with 8 thermometers, a laptop, and 2 flashlights. Ryan our vineyard manager was already out there helping the pilot wrap the aircraft to keep frost off the rotor blades and windshield. It was already 35 degrees. The breeze had dropped to dead calm. It hit freezing at 10:30. By 11pm it was 30 degrees. This was a very unfortunate development.
The goal of frost patrol in a helicopter is to find the warm air blanket 50-100 feet above the heavy cold air which settles on the floor of the vineyard and push it down into the vines. The later in the night the temperatures drop, the greater the chance of not depleting that valuable warm air. Freezing at 3am, maybe you’ll have enough warm air to push down; freezing before midnight, hmm, good luck with that.
I called the pilot and said “I hate to do this so early but let’s start flying.”
His first pass, a slow crawl at about 75 feet was amazing. At 11:25pm I was in the corner of the vineyard reading a 28 degree thermometer. Seconds after he passed in read 34 degrees. “Wow, six degrees.” I said aloud with no one to hear it. I wasn’t sure what $2,100 an hour had bought me but six degrees struck me as a lot.
As the night wore on, stopping to refuel in 2 hour increments, the impact on temperature was waning. By 5:30am the pilot was having a hard time finding any air pockets above 32 degrees. By 6:30am he was on the ground with nothing left to be done. By sunrise just before 7am the thermometers all read 27 or 28 degrees. Our tiny buds were on their own and freezing and at a rate the experts claim is 10% per half hour.
All of injury happened in the last hour and a half heading into sunrise. The Viognier got the worst of it with 20-30% of the buds getting burned. Fortunately Ryan had, in the course of winter dormant pruning, left many more buds than we would ever plan on cropping. While leaving all of these excess buds would require weeks of additional pruning by the crew, it was exactly the kind of insurance that would pay us back in spades. We start our 2016 growing season with some injury, 2 sleepless nights and a monster helicopter bill, but absolutely no regrets!