Every autumn we revel in the beauty of the trees, knowing that their beauty is only a fleeting pleasure. Quickly, the leaves will flutter down becoming part of the rich carpet covering the forest floor.
Young Greencastle residents have their own ideas about how the colors change. Five-year old Wesley Moore is a big fan of the changing leaves. When asked what made them change color he had to think for a few minutes.
"They just do, 'cause that's what God wants them to do," he finally replied.
Sara Smith, age 8, knew the cold had something to do with it.
"The cold air freezes them and they change to red and yellow. If it rains enough they turn back green," she told the Banner Graphic Friday.
Many folks believe that frost or the drop in temperature is responsible for the color change, but the scientific reason for the change is the result of chemical processes.
According to Web site www.sciencemadesimple, plants take water from the ground through their roots. They take a gas called carbon dioxide from the air. Plants then use sunlight to turn water and carbon dioxide into glucose, a kind of sugar.
This glucose is used by the tree as food for energy and as a building block for growing.
The way plants turn water and carbon dioxide into sugar is called photosynthesis. That actual meaning of photosynthesis is "putting together with light." The chemical chlorophyll then helps make photosynthesis happen. Chlorophyll is what gives plants their green color.
Trees know that winter is approaching and they begin to shut down their food-making factories. The green chlorophyll disappears from the leaves. As the bright green fades away, we begin to see yellow and orange colors. Small amounts of these colors have been in the leaves all along. They are just not visible because they are covered over by the green chlorophyll.
At the same time other chemical changes are occurring causing the formation of additional pigments that vary from yellow to red to blue. Some of these colors appear in trees like the dogwood and sumac.
Others give the sugar maple its brilliant orange or fiery red and yellow. Yet other trees like the quaking aspen, birth and hickory show only yellow colors.
Many oaks turn mostly brown and beech turns golden bronze. These colors are due to the mixing of varying amounts of the chlorophyll and other pigments in the leaf during the fall season.
Brilliant red autumn colors are created when fall weather conditions create warm sunny days followed by cool nights with temperatures below 45 degrees.
Degrees of color also vary from tree to tree based on the leaves being directly exposed to the sun or shade.
Leaves directly exposed to the sun may turn red while those on the shady side of the same tree may be yellow.
Colors on the same tree may also vary from year to year based upon the weather conditions.
The most vivid colors appear after a warm dry summer and early autumn rains.
Some of the most colorful combinations are found in the leaves of red and sugar maples, sassafras, sumac, black gum, sweet gum, Northern red oak, scarlet oak, sourwood and dogwood.
Gingko, hickory and yellow popular produce few anthocyanins and usually just display a golden yellow.
Around Putnam County if you are looking for colorful leaves, the view from the Boone Hutcheson Cemetery down on the Houck Covered Bridge can't be beat. Fern Cliff just outside Greencastle also offers a range of color amid its cliffs.
There are plenty of hills and hollows throughout the southwestern side of the county that offer fabulous view.
Karla Lawless, Executive Director of the Putnam County Visitors and Convention Center recommends a couple of gorgeous drives to look at leaves.
"Head out West Walnut Street from Greencastle toward Mansfield. About four or five miles out you feel like you are in a cave of trees. It is just beautiful," she said.
"And if you go all the way to Mansfield you can see the Rocky Fork Covered Bridge," she added.
"There is also an area out there called Dillinger's Woods. It's believed he use to hide out there and had some relatives who lived there. It's a beautiful woods," said Lawless.
Another great drive is to head toward the town of Clinton Falls.
"You can kill two birds with one stone. You can see the Edna Collings Covered Bridge and go through Clinton which has a gorgeous water fall, swinging bridge and weather station," noted Lawless.
Outside the county hit anyone of the state parks with Turkey Run, Shades and McCormick's Creek all within an hours drive.
The state of Indiana also offers some great leaf viewing from your computer. Go to www.visitindiana.com. Web cams are set in Brown County, French Lick, The Fort (Indianapolis), Lafayette and at Spring Mill State Park.