All seasons have their beauty, but October is something special. The rich palette is reminiscent of life itself — its cyclical patterns, its breadth and variety a fiery blast before the big sleep.

We’ve come just past the pinnacle of fall colors in North Idaho. While the leaves of some deciduous trees are still green, others blanket the ground. Still the splendor remains, a cornucopia of red, orange, yellow, purple, browns and — my favorite — trees sporting them all simultaneously.

The prettiest leaves have multiple colors, green and yellow, red and green or yellow, yellow and orange, or some mixture with a smattering of brown, interspersed or lining the edge. How can this be?

Leaves are green because they contain chlorophyll; think of it as fuel. This extraordinary chemical absorbs energy from sunlight, transforming carbon dioxide and water to carbohydrates. So green leaves are essentially tree food factories.

Chlorophyll’s dominant green effect also acts as a curtain, hiding the leaves’ other pigments (e.g., carotenes and xanthophyll). So when autumn’s reduced sunlight and colder temperatures (timing generally depends on nighttime lows) break down the chlorophyll, the green fades and previously masked yellows and oranges gradually emerge. Anthocyanin pigments make those deep reds and purplish colors in some trees.

Each species is chemically different, as are amounts of chlorophyll residues even in individual trees and leaves, so the range and shades of visible pigments vary. That colorful diversity is what makes fall so beautiful.

Why do leaves fall? They don’t so much fall as get kicked off. At the point where the leaf stem meets the tree, a layer of abscission (think “scissor”) cells develop which severs the tissues supporting the leaf. Before it falls, the tree has already sealed the exit point, leaving a little scar and preventing fluids from flowing past it.

Why kick them off? Trees are conserving precious resources to survive winter. Think of it as letting go of the kitchen staff in lean times, once the larder is full.

Temperature, light, and water supply have an influence on the degree and the duration of fall color. Low temperatures (above freezing) often mean more reds, but early frost weakens that. Rainy and/or overcast days tend to increase the intensity of fall colors, so if gray autumn days depress you, remember they offer in compensation this stellar artistry to enjoy.

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Sholeh Patrick, J. D. is a columnist for the Hagadone News Network whose favorite month is October. Email: Sholeh@cdapress.com