Friday 18 August 2017

Taking on Jack Frost

While Robert Browning may have wished to be in England in April, for winemakers the month can hold a nasty surprise. Dave Rackham, of East Sutton Vine Garden, in Maidstone, Kent describes the importance of taking on Jack Frost at this time of year and how the chances of frost in April can be reduced.

 

We have all now carried out our winter work, pruning, tying down, trellis checks and now watch with bated breath as the vines start to push hard; swelling the buds which carry our years hopes with them. A sparkling time of year, when sap shines like jewels as we look through our vineyards in the clear spring sunlight: magical!
These days are in many ways what a lot of us do this job for, but remember, they also bring the prospect of potential disaster – frost.
I am very surprised when visiting other vineyards when I see them well tended and ready for the year with nice hedges and very often sloping down to a nice wooded area with lots of bird cover etc. Hold on: just a minute, hedges, uncleared low areas around vineyards, surely this is a recipe for that lurking disaster?
Our vineyard is in the Weald of Kent and as such it is prone to the late re-radiation frosts that can hit any time up until mid May. I recall an absolute belter on May 5th 1992 (I think) when we woke up to the heaviest hoare frost I have ever seen, the consequent loss of virtually the whole vintage almost did for us.

April frosts
The frost described above is, thank God, a rare event, but throughout April we will get frosts that are potential vintage killers. So what to do?
The first thing is to make sure that your vineyard has a clean bottom (I’ve heard all the jokes before). By this, I mean make sure all prunings are cleared or fragged, whatever is your system. Give the grass a mow if possible. The idea being to make sure that the cold air can roll or move down your slope if you have one.
Next, make sure the cold air has somewhere to go outside of the vine planting perimeter. If you have a lower part of the vineyard, perhaps running down to a hedge or that pretty woodland, make sure that the cold air, which acts just like water, can run away from your vines by clearing out the bottom of the hedge or whatever obstacle would interrupt the smooth passage of air. It is amazing how much a few hours work can improve your overall vintage.
I do hope all of you have already done the above but if I have reminded just one or two of you to go and have a look and it saves even a row of vines, it will have been worth it.

Heavy bunches.