Season of mists and mellow fruitfulness, as Mr Kipling famously remarked from the nobly rotten slopes above the Garonne on one of his annual pre-harvest wine tasting tours.
The sun has certainly been a close bosomed friend so far this month. Rather too close bosomed for some, smothering the country in its ample cleavage in a way one doesn’t typically expect in the week the children are back at school and several weeks into the new football season, our poorly insulated bedrooms once again becoming clammy cells o’er-brimmed with summer.
But exceedingly good for English and Welsh vineyards, most of which saw an epic start to the season decline into another damp, cloudy and windy high summer. Good news for those ignoble rots and mildews that love this kind of thing. Bad news for everyone else.
My own vineyard suffered. In my last post I spoke of my forced absence from the site after breaking several ribs. That absence didn’t go unnoticed by the micro-organism community and by the time I returned in August Downy Mildew had paid a visit or two. So the ridiculous, very obviously anthropogenic heat of early September has been very welcome. The vines are growing again, the canes thickening and the few bunches I allowed to remain on the Melon and Pinots have proceeded from grapeshot to juicy grapes in super-quick time.
This isn’t the first time September has come along to save the English grape harvest. In several recent years the month has been relatively warm, stable and dry. In 2021 a near record September helped to salvage an awful, mildew-infested season for growers. The same happened in 2016 after a chilly and nondescript summer. In other years a warm September has capped off a bumper summer. Is this luck or is something else going on?
I grew up in an era of early Autumns and September chill. The early autumns of the 1980s were certainly a season of mists; I remember well the back to school fogs. But the mellow fruitfulness was harder to come by. It was on with the fur-lined anoraks and off to pick up conkers in the muddy playing fields.
I now realise that was the exception rather than the rule. The Met Office publishes monthly climate data for South and South East England going back over a hundred years. In the high summer months temperatures and hours of sunshine have been steadily rising since sometime in the 1960s. Not so September. It actually deteriorated a little from 1960 to the early 1990s. The turning point came at around the same time those first classic varieties were planted at Nyetimber. Since then and particularly during the 21st century it has rapidly caught up with the surrounding months.
Perhaps that’s why one reason English viticulture struggled so much in the post-war period. We are a cool climate with a long growing season needed to bring grapes to ripeness. If ripening ends prematurely in early September or wet weather dilutes the sugars and brings out the bunch rot it’s pretty difficult to catch up after a mediocre summer. How much more satisfying to look out over the vineyards this month, rustling in the gentle late afternoon sunshine with only the wasps, birds and those wailful choirs of small gnats known as Spotted Wing Drosophila to worry about?
Is this global warming? In part. The background trend is pretty clear. But there are some September dynamics at play too. Look at that Met Office time series, reverse out the global warming trend and marvel at how closely it resembles another (you can eyeball it or run the stats if you like): the time series of Atlantic basin hurricane activity. The Atlantic basin was busy with hurricanes in the first half of the 20th century, then went into a relative lull until about 1995, and has since been very active again.
This has a direct, though messy, impact on Western European weather. Occasionally a rogue ex-hurricane will find its way into the North Atlantic jet stream and pep up the storms and rain. That’s likely to happen a bit next week. But most of the time tropical cyclones in the Mid Atlantic have the effect of pumping up high pressure to their East, and pushing the Azores high up over Western Europe bringing sunshine and daytime warmth. Regardless what has gone before, in early September each year just as the schools go back the hurricane season gets going in earnest and our weather changes. If it’s an active season then more often than not our weather changes for the better.
Another example of the English wine industry benefiting while bad things happen elsewhere, I suppose. Enjoy it while it lasts.