The French government is to declare an agricultural disaster over an unusual early spring frost that has damaged crops and vines across the country, the agriculture minister said.

Julien Denormandie told Franceinfo radio late Thursday that the cold snap had been "particularly difficult" for the sector with "significant losses" registered.

"We are completely mobilised so that the accompanying measures can be put in place as quickly as possible," he said.

"Specifically, we will implement a regime of agricultural disaster," saying tax breaks could be envisaged as well as help from banks and insurance and warning that more cold weather could be on the way.

French Agriculture Minister Julien Denormandie says the cold snap has been "particularly difficult" for the sector with "significant losses" registered.
French Agriculture Minister Julien Denormandie says the cold snap has been "particularly difficult" for the sector with "significant losses" registered. AFP / JEFF PACHOUD

He said the situation was "quite exceptional", with vineyards hit but also other crops like beet and rapeseed in regions spanning the north of the country to the southeast.

In a bid to ward off the frost, French winemakers have lit thousands of small fires which have caused a layer of smog in the southeast of the country.

The practice of lighting fires or candles near vines or fruit trees to prevent the formation of frost is a long-standing technique used in early spring when the first green shoots are vulnerable to the cold.

Whole hillsides look as if they are ablaze, creating a striking visual effect, with winemakers scrambling this week as temperatures plunged to below freezing, particularly in the fertile Rhone valley in southeast France.

The CNIV national winemakers' association warned the situation is "one of the most serious in recent decades" and will cut production of the year.