into the coppery halls
of beech and intricate oak
to be close to the trees
as they whisper together
let fall their leaves,
and we die for the winterKatherine Towers’ Whim Wood from The Remedies
There is a long and on-going love affair between America and the changing colours of the leaves on the trees as winter approaches. They even have their own name for this “season of mists and mellow fruitfulness”: in the rest of the English-speaking world it is known as autumn but in America, it is called fall.
What might not be common knowledge is that those splendid, beautiful reds and yellows are in fact the genuine colours of the leaves – while the bright green displayed through spring and summer is actually a trick of nature.
In spring young leaves are flooded with a bright green compound called chlorophyll. Chlorophyll absorbs sunlight and carbon dioxide and water, allowing the tree to process these into nutrients. As the last days of summer approach, the chlorophyll begins to disappear, revealing the “true” colours of the leaves in their full glory.
Prosaic though it might be, beta-carotene, the same substance that colours carrots, gives us those wonderful ochre tones. Anthocyanins provide us with deep reds and glowing yellows. Flavonoids offer up pigments of gold.
As winter approaches, deciduous trees, those whose leaves fall, batten down the hatches for the advent of cold weather. As the days become shorter and the temperatures fall the trees know it is time to go into hibernation. They turn off the chlorophyll and slowly shut down the veins which carry water to the leaves, causing the leaves to gradually wither and die.
Were this not to happen then the leaves and maybe the trees themselves would freeze to death.
So nature gives us the sumptuous burst of colour which we call autumn and the Americans call fall.
If you live in the USA, or simply would like to know where and when nature’s magnificent show of gilded glory will be at its best, Smokey Mountain provides an interactive map of fall as the season approaches.
And what about those dead leaves?
They provide natural warmth and protection for the tree roots and degrade into a rich compost which, in spring will provide nutrients for the following year’s leaves so that the cycle may begin once again.
Check out the interactive 2020 Fall Foliage Prediction Map here.