Driving across the north midlands last weekend, I was astonished by the profusion of hawthorn blossoms, which seemed to be multiplying even as I passed.
In the hedgerows of Meath, they were mounting a show of force. By Westmeath, they were in open riot.But in Roscommon, it was like a Maybush revolution, in which all the other vegetation had been overthrown.
So back in Dublin since, I rang the National Tree Council to ask if it was just me or was this year's hawthorn display unusual.
The latter, they confirmed, explaining that it’s partly the result of last year’s hot summer.
There was something similar in 1996, after the sweltering summer that went before. But for the full science, the NTC suggested, I should talk to the director of the National Botanic Gardens, Matthew Jebb.
In fact, as Matthew concedes, the science is still in large part a mystery, because there are so many variables involved and because the trees themselves cannot be interviewed. But in general, of course, the current frenzy in the hedgerows is to do with reproduction. While my riot analogy might serve to suggest the excitement involved, it seems, “orgy” may be closer to the truth.
If trees do not have brains, Matthew explained, they do have an acute sense of what time of year it is.
The crucial thing for them is to be “sexually prepared” at the same time as their neighbours. But depending on whether spring is hot or cold, and other factors, there can be up to a month’s difference in when the hawthorns flower, and this year it’s happening relatively late.
What I saw at the weekend, therefore, is an arboreal “panic”, as the trees belatedly get their act together in a much more compressed time-frame than usual.
Meanwhile, yes, an effect of last summer was to produce more flowering buds for this year.
Hence the hedgerow spectacular of 2019, as the darling buds of May appear in numbers and with a synchronicity that are both unusual.
Among other things, the phenomenon may throw light on an old meteorological adage relating to this month: “Cast not a clout till May is out.”
A “clout” is a piece of clothing, and the saying is usually taken to mean that you shouldn’t dress for summer until May is over. A less conservative interpretation argues that the May in question is the Maybush, now very much “out”. If you believe that, then, in keeping with the hedgerow debaucheries, you can start casting your clouts with impunity.
It might seem logical, given all this, that the smell of hawthorn blossom is often considered sexual by humans (as indeed Michael Harding was writing on Wednesday). But the odour is notoriously ambivalent and has also sometimes been compared with that of death.
Thus a 19th-century English magazine recorded the belief among “country cottagers” that the scent of hawthorn blossom was “exactly like the smell of the Great Plague of London”.
And science may since have backed the cottagers up, since the flowers are known to contain trimethaline, one of the first products of decaying flesh.
The famously sensitive nose of Marcel Proust reflected the ambiguity. "It was in the month of Mary [ie May] that I remember having first fallen in love with hawthorns," he writes in his epic fictionalised memoir, In Search of Lost Time.
Noticing the smell in a church display, he compares it with “bitter-sweet fragrance of almonds”. But it also quickly reminds him of “the sweetness of Madamoiselle Vinteuil’s cheeks beneath their freckles”.
And in contrast with the flowers’ motionlessness, he writes of how “these gusts of fragrance came to me like the murmuring of an intense vitality, with which the whole altar was quivering like a roadside hedge”.
Later, among actual hedges, he describes the smell as “throbbing”.
I didn’t notice the bitter almonds, not to mention the throbbing, last weekend, when I stopped to take pictures of the blossom in Roscommon. I did, however, notice the tendency of the predominantly cream-coloured flowers to be pink in parts.
The combination reminded me somehow of those old-fashioned sweets of my childhood, Clarnico Iced Caramels.
And now I see that, elsewhere in his book, rhapsodising about the colour of pink hawthorn, Proust too finds himself having confectionary memories.
He thinks of a shop in Combray, a town where he spent his early years, “where the most expensive biscuits were those whose sugar was pink”.
So there. Our hawthorn experiences have that in much in common, anyway.
As Myles na nGopaleen once said of himself, I may be a spoiled Proust.