Maddy: Fall splendor: Why leaves change color and their value
Published 7:50 pm Friday, October 20, 2017
At this time of the year many people travel to north Georgia to enjoy the fall colors. The pastor of our church went all the way to Burlington, Vermont to view the changing of the seasons. You can identify trees species in the fence lines and tree lines by their colors. The bright golden yellow of the hickories and soft pinks of the sassafras are readily visible. Scarlet oaks proclaim their name brilliantly. The scenic highways will be full with tourists especially in the Smokey Mountains and Western North Carolina.
Why do leaves change color and fall in the first place? It’s nature’s way of surviving the harsh temperatures of old man winter. Unlike conifers, which have tough, wax coated needles or scales with their own built in anti-freeze; broad leaf trees have delicate, cold sensitive leaves.
As the nights get longer and the sunlight declines reducing temperature, special cork cells at the base of the leaf start to close off. When this occurs, the chlorophyll starts to diminish as the water and mineral intake slows down.
Chlorophyll is the substance that gives leaves a green coloration. As these veins seal off, leaves begin to shed which ensures the survival of the tree. Conifers or evergreens can withstand most harsh winter climates except in the Arctic.
Autumn colors come from three basic sources, chlorophyll, carotenoids and anthocyanins.
Chlorophyll essential for photosynthesis produces the green color. Carotenoids produce the yellow, orange and brown colors. Anthocyanins are produced in the fall when the sugars are trapped in the leaves as they are sealed off. These produce the common colors seen in blueberries, plums, red apples, grapes and strawberries. When the chlorophyll slows down and disappears, these other pigments appear.
Weather can affect autumn color. Cool crisp nights combined with warm sunny days usually produce spectacular fall colors. The warm sunny days produce lots of sugars in the leaves as the veins seal off. This spurs the production of anthocyanin, which produces the vivid red, purple and crimson hues.
The purplish reds of the dogwoods, the crimson red sourwoods and black gums start to make their appearance. Most fall colors are genetic to their species. Maples may produce brilliant colors such as the sugar maples painting their leaves orange-red. Sourwoods usually turn earlier in the fall whereas oaks hang on the longest.
The lack of moisture can also affect autumn color. A spring drought or summer drought may delay nature in displaying fall color. The most brilliant autumn colors are produced from warm, wet springs, mild summer weather, and warm days/cool nights in the fall.
Some tree species are bred solely for their fall color, especially the maples. Many homeowners include specimen trees in the landscape for their colors. A good example of this is the male Chinese Gingko, which lights the landscape up with yellow. Many crabapples do the same. Adding a little color to the landscape enhances the value of your home.
Some folks refrain from planting trees in their landscapes because of the leaf drop. With the advent of leaf blowers, leaf cleanup can be done quickly. Leaves make an excellent addition to the compost pile. As leaves decompose they add organic matter to the topsoil. This makes soil black in color. The last place leaves should go is on the curb or in a bag. They are vital to the forest ecosystem.
What’s going on in Extension?
- Nov. 9: Thursday Lunch-n-Learn at the LaGrange Library at noon. “Small Engine Maintenance” is the topic. Note the change from Tuesday.
- Nov. 9: MGEV Meeting “Fall Garden Maintenance Program” Open to the public. 6:30 PM at the Ag Center. Program begins at 7 p.m.
- Nov. 14: What’s a Good Hunting Lease?” UGA Wildlife Specialist Mark McConnell; 7 p.m. at the Ag Center, call (706) 883-1675 to register.
- Nov. 20: Troup County Association of Beekeepers 7 p.m. at the Ag Center.
- Nov. 21: Troup County Cattleman’s Association: “NRCS and FSA Programs” Meal starts at 7 p.m., cost $6, call ahead for reservations, (706) 443-7697. The program will start at 7:30 p.m. at the Ag Center.
Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 144 Sam Walker Dr. LaGrange, GA. 30240 (706) 883-1675. Monday through Friday/8 a.m. to noon and from 1 to 5 p.m.