On Wednesday, December 14, an ice storm of historic proportion struck the Willamette Valley with fierce intensity. Freezing rain coated wires and branches until they could no longer bear the weight. With an audible crack as the only warning, power lines and tree limbs came crashing down across the valley. Miraculously no one was injured, but a quarter of the area’s homes were without power for anywhere from a few hours to a week or more.
Unlike trees with vulnerable branches, the trellises the grapes grow on support much of the structure of the vine. The valley’s orchards were hit hard but our vineyard suffered little damage. Power went out for a couple of days, but because we were through fermentation, we didn’t need electricity for heating or cooling. If necessary, we would have brought in generators to keep essential operations going.
The ice storm was both beautiful (as the photo above snapped by Jodee King shows) and destructive, and the vines basically slept through it. As Director of Winery Operations and Viticulture Ray Nuclo explains, dormancy is a process that peaks in January and February, but the vines are well on their way to sleep in December. The temperature in the Lorane Valley was 26 degrees at its lowest point this month; only when it gets down to less than 10 degrees do we worry about damage to the vines.
Grapevines are hardy, but they can suffer damage in extreme cold. The two greatest risks are trunk damage and bud mortality. Trunk damage can cause the loss of the whole vine, which is serious, but it wasn’t cold enough for that to happen. (Ray recalls a situation in early 2014 when temperatures fell low enough to potentially damage the trunk at the vulnerable point where the fruiting wood, or scion, is grafted to the rootstock, but there was snow cover that provided enough insulation to protect it.)
Bud mortality is just that – dead buds where the shoots would eventually form (or not). The vines have buds even at this point in the growing cycle. Had temperatures fallen into the danger zone we would test the buds to see if they were green (alive) or brown (not). Because the temperature stayed well above 10 degrees no testing is called for.
Another threat to the vines in cold weather is a bacteria disease known as crown gall. It can be triggered by cold damage to the trunk, but temperatures stayed high enough to avoid this problem.
By Monday, December 19, the winery was back to normal. The wines were tucked safely in the cellar, tanks or barrels as the sun peeked out to melt the ice. The fireplaces in our Tasting Room and Restaurant were once again ablaze, warming hearts and lifting spirits as people ventured out and continued to celebrate the season.
From all of us at King Estate, happy holidays!
