Autumn: The Greatest Show on Earth
A behind-the-scenes look at the award-winning production
If you’re like me, every year you declare spring your favorite season. My favorite, that is, until autumn arrives.
After weeks of watching my garden favorites decline in splendor, autumn quietly slips in the garden theater’s side door, positions herself center stage and prepares to help me forget all about it. And forget, I do.
Those fading zinnias with their nappy leaves? Whatever. The once towering amaranths need staking? Again? I shrug and turn my gaze back toward autumn. I know her performance by heart. Yet, it never ceases to produce anticipation and inspiration.
Anyone who knows me well, knows that when it comes to the intrigue of science and nature, I am a five-year-old trapped in a forty-year-old’s body. The incessant questions of curiosity no longer pass my lips as often, much to the relief of friends and family, but they’re still there. I find that understanding a spectacular natural event, like autumn, doesn’t diminish its grandeur, it only reinforces it. Don’t you? Let’s reinforce the grandeur, shall we?
During the growing season, it’s the chlorophylls, those overachieving pigments in the chloroplasts of leaves, that are responsible for the green color we primarily see. They are the main players in capturing the sun’s energy for use in photosynthesis (and a great Halloween costume idea for your budding biologist). But they’re not alone. Carotene and xanthophyll are there too, only in much fewer numbers, happily absorbing energy and reflecting orange and yellow light, respectively. Overshadowed, they wait.
The plot thickens when, seemingly overnight, cooler nighttime temperatures and shorter days enter the scene.
Phytochromes, remarkable light sensing mechanisms in leaves, detect shorter days indicating that winter’s freezing temperatures are near. Defensively, the plant swiftly and efficiently prepares to shut down the whole food factory until spring, when conditions are more favorable for food production. Well, isn't that clever!
A flurry of activity ensues. A separation layer of cells begins to form in the petiole, where the leaf attaches to the twig, blocking the flow of nutrients into the leaves and sugars out. The grand finale is imminent.
Chlorophyll production is arrested, unmasking the brilliant yellow and orange pigments. Oooh, ahhh!
Anthocyanins, the pigments responsible for the bright reds, purples and pinks, rush the stage. Oooh, ahhh!
On the edge of my seat, I soak it in for what never seems long enough. Then, right on cue, the separation layer fully forms (except in those pesky oaks) and the leaves drop, blanketing the theater’s floor in warm hues. Bravo! Bravo!
Yep, no doubt about it. Autumn is my favorite season. That is, until spring arrives.