To deleaf or not is the question this year in Bordeaux. There is a lot of vegetation yet the risk of scorch with the exceptionally hot temperatures has been high.
In Bordeaux luckily mostly the leaves have been left on the vines so far and act like an umbrella covering the pea sized grapes which are swelling every day and filling out the bunches (effeuillage has not really started across the board yet).
This will avoid scorch of these little berries. Once this extreme heat has passed the leaves will be ripped off by hand particularly on the ‘morning’ side of the row of vines so the gentler morning sun can ripen the grapes directly but leaving the leaves on the other side protecting the grapes from the harsher afternoon sun (these get removed only at start September normally when the sun is less strong). The roots of adult vines go down several metres so the vines are very resilient to dry hot periods (hence there is no need to irrigate – very much against the french rules!
In prolonged drought conditions (such as 2003) the vines become blocked and ripening stops in an attempt to survive and the leaves wilt and go brown.
So far 2019 vintage Bordeaux; There is good yield and the flowering went quite well so far (a little coulure and millerandage particularly in the sensitive Merlot – the green berries do not pollinate properly and drop off or stay in the bunch – due to the cold May temperatures and some rain during harvest).
The hot weather in Bordeaux (and the rest of France) is set to continue (its been since around 25th June so three weeks or so). Max temperatures have been up to 42°C which has been unheard of and the nights have not cooled substantially for the vines to have a rest. They have begun to tire and slow down the long race to the harvest line – still some way in the distance. Its not normally until start of October that the grape picking starts on the right and left bank.
Prolonged Temperatures in the 40s are rare in Bordeaux particularly in June and July. Extreme photos of scorching of vines south of Bordeaux in the Mediterranean have been widely publicised but here the vines have not suffered (roots go deep here in Bordeaux’s vineyards delving down several metres in search of water which makes them quite resistant). The continually hot temperatures have however slowed down the vine’s metabolism.
Finally on Friday 26th July we had some welcome heavy rain and cooler temperatures back down to the mid 20s. The rains have come, a relief after a month’s heatwave. The vines can breathe again (us too) and have welcomed a cool drink before the ripening race starts again. At Château Beauregard in Pomerol (a particularly hot microclimate and one of the first to start picking), véraision has started – that is the changing of the colour from green to red.