After the vines are pruned, the buds on the vines begin to swell, and eventually burst open, tiny leaves unfolding into the world, clusters of a new vintage. These new buds must be protected fiercely—mainly from frost. In the spring, temperatures can dip down below freezing, (mostly overnight and in the early morning hours) and must be watched carefully. If frost reaches this new growth, the entire crop can be wiped out. There are two main ways now that these buds are protected from being destroyed by frost season.
Wind Machines: Wind machines mix warmer hair from above with cold air from below. Mixing these inversion layers result in a more moderate temperature to protect the tissues of the buds from frost damage. It also helps ventilate the growing area of the vineyard, and helps prevent pools of cold air from forming on or around the plant surfaces.
Spinklers: When water is sprayed in freezing temperatures, it freezes around the plant material and green tissues—and releases heat in this process, protecting the buds. A constant and large amount of water is needed for this method (sprinklers), to create a freezing coating around the vine buds and shoots to release enough heat and raise the temperature to protect them.
**Before frost alarms and weather stations, farmers stayed up all night, lighting smudge pots and monitoring the temperature. Smudge pots are oil burning devices placed in and around the vineyard creating warmth and smoke to raise the temperature around the new growth. They are no longer used, but you can still see them scattered throughout the valley, typically next to endposts, or on the edges of vineyards. Even though there are devices that help predict freezing temperatures and automations that make this all easier than the past, this time of year is still incredibly stressful protecting the vines. A cup of coffee and some patience goes a long way in the spring ;)
