On a drive through the Carroll County countryside the other day, WTTR was playing “The Mamas and the Papas” 1966 hit song “All the leaves are brown and the sky is gray” on the truck radio; but outside along the road, Mother Nature did not get the memo and was still dabbling with yellows, oranges and brilliant reds in the trees.

This year, the autumnal equinox, the first day of fall, began on September 22, at 4:44 p.m. That’s when the sun is aligned with the equator making days and nights equal in length.

The arrival of fall is a storied event in American history, folklore and tradition; however, one of the more interesting musings comes from Tom Robbins, the author of “Still Life with Woodpecker.”

Robbins wrote, “It was autumn, the springtime of death…”

Okay, well anyway; as old man winter approaches, there is arguably no prettier season in Carroll County than the vibrant tree leaves of fall. This is when, for a short period of time, trees are allowed to act-out and show some additional passion with a dazzling wardrobe of color.

A point not lost on Susan Williamson, the visual arts coordinator at the Carroll County Arts Council.

“Artists use the colors of nature as inspiration for their own palette. No better time to watch Mother Nature change her palette than in the fall for the exquisite colors in Carroll County. Our rolling hills make for a variety of virtual-canvases to show off the changing colors in the fall,” Williamson said.

“Carroll County is such a lovely county,” adds Bonnie Staub, the manager of the Carroll County Office of Tourism, “but this time of year, it is more beautiful with the changing of the leaves. It is always interesting to see each year the different colorings.”

Actually, trees have that brilliant wardrobe of colors hidden in the closet all through the spring and summer. While it is widely believed that the cooler weather causes all those beautiful shades of red, yellow, purple, and brown to come out, temperature is only one small ingredient in the complex opera of events the great painter in the sky uses to color the trees.

To be certain, colder weather or frost plays a role in the intensity of the colors, but the main factor is length of day. Trees and the food manufacturing process of leaves is very sensitive to the amount of light they receive and as the days get shorter a whole cascade of chemical – hormonal – events begin.

Trees actually stop “growing” around June. At that time, they set next year’s leaf buds and begin planning for next spring. The rest of the summer trees stay busy manufacturing and storing food, in the form of complex sugars, called carbohydrates to support next year’s growth. The food is stored in the branches, roots, and buds of the tree.

The main chef of the spring and summer food preparation process is chlorophyll. Chlorophyll is actually a generic name for a member of the tetrapyrrole family of organic compounds. It is the green-colored photoreceptor of light energy in the actual food manufacturing process called photosynthesis. 

The organic compound chlorophyll is manufactured and replaced constantly throughout the spring and summer. It only uses the red and blue wavelengths of sunlight to prepare the food-sugars. The green color of the leaf actually serves to protect the food manufacturing process from getting to much ultraviolet light.

As the nights grow longer, there is not enough sunlight available for the food manufacturing to be efficient, plant hormones - the plant administrators, cause an abscission layer to form at the bottom of the leaf blocking raw materials from entering the leaf.  Since no raw ingredients are arriving in the leaf, the chlorophyll begins to get tired and breakdown.

As the chlorophyll goes away, the presence of the other pigments are revealed, said Steve Allgeier, the horticulturist for the Carroll County office of the University of Maryland Extension.

“The chlorophyll normally masks the yellow pigments known as xanthophylls and the orange pigments called carotenoids.  Red and purple pigments come from anthocyanins,” Allgeier said.  

“You know,” added Allgeier, “the university, the Westminster Tree Commission and the Carroll County Forestry Board all encourage fall tree planting. I mean, if you like fall colors and you want to add fall colors into your landscape, now is the time to plant deciduous trees. Planting season unusually lasts all the way into December.”

When all the leaves are brown and the sky is gray…

When he is not driving through the countryside admiring Carroll County’s fall colors, Kevin Dayhoff may be reached at kevindayhoff@gmail.com