This time of year, a common question I hear is, “When will the Fall colors peak?” Unfortunately, the answer is a moving target because there are so many factors that cause our oaks and maples and dogwoods to change from green to yellow, orange, or red.
I used to think that cool weather or frost cause the leaves to change color. While temperature may dictate the intensity and duration of fall color, turns out it is only one of many environmental factors. Like most plants, deciduous trees and shrubs are rather sensitive to the length of darkness each day. As days begin to get shorter and nights longer, the production of chlorophyll slows and then stops. In a relatively short time period, the chlorophyll disappears completely. (As I’m sure you all remember from Elementary school science, chlorophyll is what makes the leaves green.)
Temperature, sunlight, and soil moisture all can influence the quality of the fall foliage display. Abundant sunlight and low temperatures cause the chlorophyll to be destroyed more rapidly. Cool temperatures, particularly at night, combined with abundant sunlight, promote the process that causes the trees to shed their leaves. Drought stress during the growing season can sometimes cause leaves to drop before they have a chance to develop fall coloration. Wind and heavy rain may cause the leaves to be lost before they develop their full color potential.
The ideal weather conditions for the brightest fall colors are a growing season with ample moisture that is followed by a rather dry, cool, sunny autumn – marked by warm days and cool but frostless nights.
So there you have it – clear as mud! That darn Mother Nature just isn’t very predictable!
Fall Color updates around Arkansas and at the Tall Pines: