Our palette of fall!

                       Gently falling, fading—gone

                       Save in grateful eyes.                  

 

Haiku poem by NJB

 The first greenings of spring, in their endless variety of forms, represent a “color of relief.” We sense the promise of consistently warmer days and a new growing season. The beautiful turning of leaves in fall seems one of the consolation prizes we are given to soften the dread of winter.

Several factors influence fall leaf color: increasing night length, steadily lowering temperatures, and leaf pigments. Color intensity is enhanced by ample rainfall and by steadily falling, but not suddenly freezing, temperatures.

Genetics determine why certain plant species or fruits turn certain colors, but the astronomically-based trend of steadily longer nights during fall is the big unvarying factor in the equation. I’ll see genetics in action in late October as I drive south from OH to SC. The leaf color of any given species of tree or shrub will be essentially the same whether I see it at a warmer 1,000 feet altitude or at 3,000 feet or more while driving through the Appalachian Mountains.

Chlorophyll, during the growing season, constantly is being produced and broken down. Chlorophyll production slows down and eventually stops as night length increases and temperatures drop. Other pigments are unmasked.

The carotenoid pigments, present along with chlorophyll during the growing season, produce the yellow, gold, orange, and brown colors we see in some leaves, and in corn, carrots, daffodils, rutabagas, buttercups, and bananas.

The anthocyanin pigments, most produced in leaves as days shorten and nights lengthen, give their colors to some leaves and to cranberries, red apples, plums, concord grapes, blueberries, cherries, and strawberries.

Genetics play the big role in determining the combination of carotenoid and/or anthocyanin pigments present in ripe fruit and in the “leaves of fall” for any given species of plant. Many beautiful processes are in motion as plants and animals prepare for the cold. The most obvious, and beautiful, as trees and shrubs shed their most vulnerable parts, is Our Palette of Fall.

Please press a red one for me.