‹‹ Colorado Postcards

Fall colors

Listen Now
1min 00sec
Hart Van Denburg/CPR News
A view of fall colors on Vail Pass, Sunday, September 16, 2021.
Fall colors

Colorado’s aspen, cottonwoods and poplars shimmer in gold each fall. Scrub oaks are burnished in russet. You’ll also see splashes of crimson, scarlet and magenta dotted across the state.

But the leaves don’t actually change color in the fall. The green chlorophyll in them simply begins to break down, and that unmasks the underlying yellow, red and orange pigments that have been in the leaves all along. Each leaf’s autumn color depends on its predominant phytochemicals – yellow flavonoids, like lemons; red and orange carotenoids as in tomatoes and carrots; purple and magenta anthocyanins, found in grapes.

A stretch of warm, sunny days and cool, crisp – but not freezing – nights tend to make for the most spectacular autumn hues before the leaves fall, infusing the soil with nutrients to begin another cycle of changing seasons in colorful Colorado.

About Colorado Postcards

Colorado Postcards

Colorado Postcards are snapshots of our colorful state in sound. They give brief insights into our people and places, our flora and fauna, and our past and present, from every corner of Colorado.