Mild winter exposes French growers to increased spring frost vulnerability

Candles in a vineyard to protect from frost damage
Candles can be used to protect vines from frost damage.

‘It’s been warm since the 15th of December, with nothing below zero for several months,’ said Tom Warner from Domaine de Joÿ in the Southwest. ‘It’s worrying.’

His comments are echoed across the country, but particularly in the more northerly appellations, where growers are eyeing their vineyards with concern.

‘We’ve already started budding and that usually happens at the start of April,’ said David Depuydt of Domaine de la Genillotte in Chablis in early March. ‘We’re a month ahead.’

Figures from Meteo France starkly illustrate what vineyard owners can tell from tramping the rows every week: this winter has been almost non-existent.

Temperatures are, on average, 2°C higher than usual, with February particularly mild at 3.6°C above the average – something that the body describes as ‘more worthy of the spring period’.

March, meanwhile, saw temperatures in the high teens across the entire country.

Though harmless in themselves, these super-mild winters come with a significant negative. Namely, if vines start their vegetative cycle early, they can be at their most vulnerable in April when frost is still a real possibility.

‘Spring is coming to our vineyards already, and it’s not until mid-May that we are free of frost,’ said Sophie Bertin from Domaine Eric Louis in Sancerre.

If you want to see how this can play out in a particularly bad scenario, look no further than 2021. A mild winter and particularly warm March saw vines across the whole country burst into life weeks earlier than usual, before a brutal cold snap in early April saw three nights of temperatures well below zero.

With many grape varieties in an advanced stage of budding, the effect was deleterious, with an Arctic black frost (airborne rather than moisture driven) simply burning off the young shoots. Some growers lost almost their entire year’s production in the space of three days. At 37 million hectolitres, France recorded one of its smallest harvests for decades.

Such events used to occur once in a generation. But they’re increasingly common. Five vintages out of the last 12 have been affected by frost during flowering to some degree, with 2017 another ‘black frost’ nightmare. And growers know exactly where the problem lies: climate change.

‘Frost in April isn’t exceptional,’ said Thiébault Huber, a grower in Meursault and president of the Confederation of Appellations and Winegrowers of Burgundy (CAVB). ‘The problem is summertime in February and March.’

Of course, there are some measures that growers can take to circulate the air and disperse pockets of frost. Fans, for instance, or bougies (paraffin candles). Images of these blanketing winter vineyards at night are an arresting sight – albeit an unwelcome one. However, both these measures are expensive. Fans can cover areas of around 5ha and cost approximately €40,000.

‘It’s €2,000 per hectare for candles, and I’ve got a 38-hectare estate,’ said Estelle Roumage from Château Lestrille in Entre-Deux-Mers, Bordeaux. ‘So to cover all of it would cost me €76,000 for one night.’

As a result, growers tend only to use frost protection when they’re 100% certain it’s needed, and even then only for the most lucrative vineyards, that go into providing fruit for the highest priced wines.

A mild winter plus springtime frost scenario is obviously disastrous for the vignerons, who can be left staring at a severe cut in income before the growing season has even properly got going. But they’re also bad news for the wine buying public.

Many regions are struggling with abnormally sized vintages on a regular basis. Lower volumes and higher costs inevitably means higher prices.

The most extreme example is Burgundy, which has lost the equivalent of three year’s worth of production over the last decade. This has had an obvious and understandable impact on pricing, as anyone who’s tried to…

Source : https://www.decanter.com/wine-news/mild-winter-exposes-french-growers-to-increased-spring-frost-vulnerability-525186/