“Taille tôt, taille tard, rien ne vaut la taille de mars !", this old precept advocating late pruning, when spring awakens the vine from its winter slumber, is now more than ever on the agenda.
Global warming disrupts the physiological cycle of the vine, including its vegetative cycle, the first stage of which is the “débourrement” (budburst), normally between mid-March and early April: buds formed on the shrubs begin to open and let out of their “bourre” which protects the fragile first shoots.
Global warming is recurringly translated into too mild winter periods that cause early budburst, resulting in an increased risk of destructive frosts occurring in April or even early May. The pruning of the vine, too generally practiced during winter dormancy from December to February, is an essential act for the life of the vine (it causes the sap to re-circulate through the vine) and for the production of fruit in quantity and/or quality.
In the face of the risks associated with global warming, pruning is now more and more often pushed back after possible frost episodes, thus delaying the debudding, foliage growth, flowering, the development of bunches of grapes and consequently their ripening, thus avoiding early harvests during the worst of the heatwaves.
Pruning and budburst are obviously variable depending on the climatic regions – more or less fresh or hot – from the terroirs – more or less prone to frost, well-ventilated or wet – and grape varieties – whether early- (chardonnay, sauvignon, gamay, pinot noir, etc.) or late-ripening (grenache, syrah, carignan, murvèdre, etc.) – but also on the practices of the vines.
More than ever, the spring season and the accompanying viticultural work are decisive for the future of the vintage, both for the development of the vine and the production of grapes during the summer, and, finally, for the nature of the vintage at the end of the summer or the approach of the autumn, before a new winter cycle begins..