Chill nights await at the crescendo of another year
It has been a dreary, drizzly autumn so far, boasting few of the traditional joys of the season.
But as the low pressure finally shifts and the seemingly incessant rain of recent weeks begins to abate, I have started to notice the leaves and the crisp scent of decay in the air.
In particular, two trees visible from my garden have caught my eye: silver birches, only 30ft apart and separated by a brick wall but apparently occupying parallel universes.
The older, larger, tree is now a beautiful uniform caramel colour and shedding leaves fast, whereas the younger tree remains nearly all green, its susurrations still those of a late summer’s day. Put it down to youthful exuberance, perhaps, or more likely because it occupies a sunnier spot.
Two predominant factors determine leaf fall: temperature and day length, both of which are now dropping fast.
Trees rely on molecules called phytochromes to detect changes in day length and possess cellular temperature gauges to measure heat at night. As soon as a particular species registers a significant fall in the requisite levels of both it begins to recycle its leaves for nutrients in preparation for the long period of dormancy to endure the winter ahead.
Man and tree alike should be braced for some chilly nights over the coming days, with patches of fog and frost in some places.
In another week – not that the trees will care – the clocks go back for winter. Expect the delayed shades of autumn to soon burst into life, or should that be death?
“Every leaf speaks bliss to me / Fluttering from the autumn tree,” wrote Emily Brontë in her poem Fall, leaves, fall.
The crescendo of another year is nearly upon us; the soft, silent rush of a landscape going for gold.