Since the water was taken off of the bogs, we've had to keep one eye on the development of the buds for this year's growth and the other eye on the weather forecast. Because the air temperature in the bogs tends to be lower than the temperature outside the bogs at night, our guys are frequently on frost watch during this time of year.
How it works is this: depending on the forecast--if it's going to be clear, cool, and calm--the farm manager sets a time for someone to go out and monitor the thermometers that we have set in the vine canopy all over the farm. When the temperature gets close to cold enough to damage the developing buds (the more the buds open, the more susceptible they are to cold--the buds are those dots in the middle of the leaves in the picture), the frost crew is called in to start the sprinklers.
When water freezes on the vines, it maintains the buds at a warm enough temperature to keep them from being damaged. The sprinklers are run until the ice melts in the morning.
Some growers use more high-tech methods than we do. There are temperature sensors available that can be monitored via computer, some that call the grower when the frost temperature is reached, and some that will start the pumps automatically. (We're investigating our options, but because we need to have people out to handle the water for the pumps, we'll probably never eliminate the human element at our place.)
