The vines are waking from their winter slumber, frost fans are starting up and the roller coaster ride to next vintage has started, with the first bud burst taking place in our chardonnay vines at our Outpost Vineyard (pictured) - Omaka Valley, Marlborough, New Zealand.
Bud burst refers to the period in early spring during which grapevines, which have been dormant through the winter, first begin to produce new shoots. During the bud burst phase, the vines are quite susceptible to frost damage.
Our viticulture team is gearing up for their busiest time of the year, from now on in it's going to be a case of keeping a good watch on the forecast. Spring frosts are one of the biggest dangers we face in the vineyard. Frost at this time can kill the foliage right back to the cordon or partially kill the shoots and inflorescences, resulting in significant crop losses. If an overnight frost is predicted, Spy viticulturist Adam and the team work around the clock to protect the baby buds from frost damage. They can be up all night checking that the frost fans are going and stoking small chimney fires to warm the vines and stop the frost from settling.
Helicopters are another method often used in Marlborough. They hover above the vines and the down draught from the helicopter causes the slightly warmer air layered above to circulate amongst the vines, reducing the likelihood of frost damage. It is not unusual to wake to the hum of helicopters hovering around 4am on a frosty spring morning in Marlborough!
We had a slightly warmer August than the long-term average resulting in warmer soil temperatures and only six ground frosts. As these were before bud burst they didn't pose a threat. The highest risk period usually falls around the full moon when skies tend to be the clearest the next falling on 25th September.