RIDGEVIEW VINEYARD MANAGER: MATT STRUGNELL
Bud burst has happened, and a green hue starts to appear in the vineyard as this year’s new growth emerges. The vineyard takes on a different appearance at this time of year. There is one thing that is high on the agenda and that is the potential for a spring frost. At this stage, after bud burst, the critical night time temperature is -1 degree Celsius. If the temperature was to get as low as this, we would expect to see some damage occurring.
We use a professional weather forecaster to help us predict whether this is likely to happen. We also have a weather station in the vineyard that enables us to keep an eye on temperatures throughout the night. The weather station will send an alarm via text message at a set temperature. If it looks as if we are in for a frosty night, our tried and tested ‘bougies’ (French for candles) are deployed ready for lighting. We need about 400 of these to offer adequate protection, so we will be watching the temperatures to allow us enough time to get the bougies lit, before it gets too cold.
There are many hours spent waiting; Bougies aren’t cheap and each one lasts about 8 hours, so it isn’t just a case of lighting them on the off-chance. We must make the most economic use of them to ensure that we have enough to last us for the whole of April and May. So, it is a case of staying awake and monitoring and waiting, constantly checking the temperature, watching the forecasts throughout the night. There are many things to consider such as the likelihood of cloud to move into the region. This has happened on a couple of nights already this spring; we may have been anticipating a frost event to occur but having cloud move in can raise the temperature by a few degrees which means that the frost risk has passed. Conversely a night can start cloudy, but we will be looking out for clear spells to develop in which case the temperature can fall to damaging levels.
There is an alternative that we have been trialling, and so far, this year with very positive results. This is the use of electric trace heating cables. The fruiting canes of the vines are tied to these, and they are automatically switched on by a thermostat. We need to properly evaluate the economic and environmental benefits of installing this system further.
Think for us until the end of May if the temperature drops, what you might see as a beautiful spring morning may have meant we were up all night protecting our precious budding vines. The ups and downs of cool climate viticulture!
If you would like to learn more about our dedication to the vines please join one of our tours