Where’s the fall color?
Published 6:00 am Friday, October 19, 2018
I can’t believe it’s this late in the month of October and the autumn colors in our region have failed to appear. I never remember a year so green this late in the season. Every day I get up and look out to see if any changes have taken place. It just doesn’t seem right to be this green at this time of year.
I have cousins coming down from Michigan who try to come at the height of Kentucky’s leaf season. They’ll be here in a few hours. Won’t they be surprised? (And disappointed.)
Some say the rainy summer has caused the delay. Some are saying the leaves are just going to turn brown and drop off this year without color. I surely hope they are wrong.
In our region of the nation, especially in southeastern Kentucky, southwestern Virginia, and northeastern Tennessee, we have one of the most diverse tree populations in the country. The combination of hardwoods and softwoods usually provide for a color spectacular among the foliage. A few on our list of trees that change color are aspen, ash, dogwood, elm, a variety of fruit trees, gingko, hickory, maple, oak, poplar, redbud, sassafras, sweetgum, sycamore, and walnut. These are among our species of deciduous trees, which lose their leaves every fall and then grow new leaves in the spring.
The changing of fall colors almost feels like magic as the green leaves of summer turn to gold, orange, and red in the fall before they turn brown and fall off. This process usually starts in our region during late September, October, and November. There is a reason these color changes take place and is the result of changes in photosynthesis.
Photosynthesis is the process that allows plants to use sunshine and convert it to food and energy for the plant, as well as the nourishment they get from the soil and water. The green part of the plant in the leaves, called chlorophyll, is the part that allows the plant to convert these things to the food the plant needs to live. As long as the leaves can soak in sunshine and heat, they stay green, but when that changes in the fall and they have less sunshine and colder temperatures, the tree begins to adjust to these changes.
Instead of working harder to try to keep making food to keep the plant alive, the trees begin to use up energy they have stored over the months of warmth and sunshine. When the changes come of shorter days and less sunlight and colder temperatures, the leafy deciduous trees begin to form a layer of cells at the base of each leaf that will slowly separate them from the tree. I’ve heard it described as a layer kind of like a fingernail that protects the tip of the branch when the leaf is gone.
While this change in the tree is taking place, is also when the colors show up. It’s hard to believe that the colors we see in fall are inside the leaf all along but hidden by the presence of chlorophyll which allows the leaf to make food and makes the color of the leaf appear green. The color actually comes out as the chlorophyll dies off. When all of the food made by the leaf is gone, it will turn brown and fall off.
In some years, the process is longer when there is plenty of sunshine, dry weather, and cooler nights and we get to enjoy the color changes for weeks. Since this year’s season has had an abundance of rain and the temperatures at night have just now begun to drop, it will be interesting to see how much color we have and how long it lasts. My camera and I are ready!
Reach longtime Enterprise columnist Judith Victoria Hensley at firstname.lastname@example.org or on Facebook. Check out her blog: One Step Beyond the Door.