Temeratures have plummeted to -6°C in Burgundy over the last two days. A few days before Easter temperatures were up in their low 20°C leading to an early bud-burst.
What was once considered a rare event, is now – due mainly to global warming- becoming a recurrant phenomena. Warm temperature in March lead to an early flowering of fruit trees and vines. The saying in France is that a late frost can happen until early May.
Wineries used to burn hay bales, which produces a lot of smoke and complaints from people living nearby, but have now turned to oil candles, which a less smoke-enducing but more expensive!
Just to clarify, frost drops on the buds react to early morning sunlight and heat and the ice on the bud starts to melt, prevoking a burning effect on the buds and damage to the plant tissue.