Issue link: http://read.dmtmag.com/i/402796
6 6 V I N E YA R D & W I N E RY M A N A G E M E N T | N o v - D e c 2 014 w w w. v w m m e d i a . c o m he first of many gauntlets that growers must pass through in a year of wine grape production is spring frost following bud break. Green tissue of grape plants is easily damaged even after relatively short exposures to temperatures below 32°F. M o s t g r a p e g r o w e r s i n m y r e g i o n – C a l i f o r n i a 's Mendocino and Lake coun- ties – believe that the higher elevations and clean air give our wines a bright, crisp and f r u i t - f o r w a r d q u a l i t y t h a t comes from sunny days and cool nights. The downside is that our spring weather tends to bring frost, espe- cially when we are having dry spells and humidity, and dew points are low. As dark- ness falls, temperatures also drop, and frosts are a prob- lem. When the weather is more humid, the dew points are higher and temperatures are less likely to fall, due to the moisture in the atmo- sphere that retains heat. BY GLENN MCGOURTY + Green tissue is easily dam- aged even after relatively short exposures to tem- peratures below 32°F + Frost protection with sprin- klers is effective, but it requires a lot of water. + The winter of 2013-2014 was among the driest ever on the North Coast. + Advances in electronic weather monitoring are making it less expensive to set up specialized weather stations in vineyards to pro- vide real-time data. + A research project at the Mendocino Vineyard Co. is testing the use of copper and copper/stylet oil mixes as a way to protect vines from freezing. AT A GLANCE W a t e r i s s u e s , r e g u l a t i o n s a n d n e w r e s e a r c h i n s p i r e a l t e r n a t i v e m e t h o d s The Ever-Changing Challenges of Frost Protection The green tissue of vines is very susceptible to freeze damage.