I love spring when the newly greening plants erupt from the soil. Summer has its place with burgeoning temperatures and longer days, and winter is beautiful when the landscape is coated in snow. But hands down, my favorite season is fall.

Fall has it all. Daytime temperatures are still warm but the nights are cool enough to sleep snuggly. Color in the landscape abounds with late blooming asters and chrysanthemums, and the smell… well the smell is incredible.

What Is it About Fall?

When I was a kid a million years ago, fall’s arrival was heralded by the aroma of burning leaves and other yard detritus. Fast forward light years and while burning in the city is now illegal there remains a smell above all others that I adore: the decay of fallen leaves.

I know decaying leaves doesn’t sound very romantic — in fact it sounds a bit macabre — but it turns out that there is science behind this elusive aroma. The decaying of fall leaves and other plants is chemically, biologically and psychologically entrenched in people. It all comes down to the sense of smell really.

When we smell something, receptors in our noses pick up aromatic molecules from the air. In the summer, hot, muggy air holds more of these scented molecules so when we breathe in we are assaulted with a miasma of aromas; so many it is difficult to pick any one scent out.

In the fall however, the cooler drier air allows us to smell more specific scents… that and the fact that there are fewer trees and plants blooming and growing. So we can more easily pluck out specific aromas such as that of leaves decaying.

Emotional Olfactory Response

The smell is then emotional, as it triggers the brain to recall memories associated with it. Now of course, for some people the smell of fall leaves might be unpleasant (or they are allergic), but to me it reminds me of playing in leaves with my sister when we were children.

So what do decaying fall leaves smell like? Well it would be different for different people but the science behind the aroma is that as leaves decay their sugars break down which to my nose at least, results in a musky/sweet scent.

Just writing about the smell has me recalling my childhood. The crunch, crunch of my boots through the dead leaves and our shrieks of laughter as my sister and I plowed into a pile freshly raked up by my father.

So, way before there was a pumpkins spiced latte available on every corner, the smell of rotting leaves is what reminds me of fall and I still love it.