If you are managing a vineyard, Spring can be a very scary time. When the vines start to wake after the winter, tender plant growth starts to develop. And this is the time when a late frost can wreak havoc on this young growth. If the air temperature drops below 32°F, ice can form in the buds which have begun to break and in young shoots and leaves. The affected parts turn brown and die, and there will be few grapes in the next harvest. The vine may respond by trying to grow more shoots from basal buds (small buds at the bottom of the vine canes), but the resulting vines are typically much less fruitful.
There are a few things that can be done if a frost is expected. Smudge pots with smoky fires can provide local heating and improve the circulation of air. Wind machines (or even helicopters) can help mix the cold air close to the ground with warmer air slightly higher up. Spraying water onto the vines can also help. But these are all expensive options.
In North Georgia, there is a history of late frosts (during the month of May). At the Blairsville monitoring station of the US Government Weather Service there have been late frosts 31 times in the last 50 years. Around Cavender Creek vineyard, 16 miles further south and lower in altitude, things are not quite as severe. The nearby UGA weather station at Three Sisters vineyard records only one May frost is the last 14 years.
Since Cavender Creek has a very favourable location, more sheltered than the local vineyards closer to the Appalachian Ridge line, the late frost issue is even less of a worry. How much happier for us than the situation in French vineyards in Bordeaux, Loire, Champagne and Burgundy have recently had a catastrophic freeze.