Friday, September 28, 2018


Dear Readers:

Came across this article on the Farmers Almanac website about why leaves change color.  Below is an excerpt from that article, with a link provided to the complete article.  If you have school age children, this might make an interesting article for them to read.
Ever wonder why leaves change color in the fall? Or when exactly they change and how the process occurs? Let’s take a close-up look at fall leaves!

Why do Leaves Change Color?

First of all, not all leaves turn vivid colors in the fall. Only a few of our many species of deciduous trees—notably maple, aspen, oak, and gum—produce stellar performances for our annual autumn spectacular in North America. 

Several factors contribute to fall color (temperature, precipitation, soil moisture), but the main agent is light, or actually the lack of it. 

The amount of daylight relates to the timing of the autumnal equinox

As the autumn days grow shorter, the reduced light triggers chemical changes in deciduous plants causing a corky wall to form between the twig and the leaf stalk. 

This corky wall, or “abscission layer,” eventually causes the leaf to drop off in the breeze. As the corky cells multiply, they seal off the vessels that supply the leaf with nutrients and water and also block the exit vessels, trapping simple sugars in the leaves. The combination of reduced light, lack of nutrients, and no water add up to the death of the pigment chlorophyll, the “green” in leaves.

Once the green is gone, two other pigments show their bright faces. These pigments, carotene (yellow) and anthocyanin (red), exist in the leaf all summer but are masked by the chlorophyll. (The browns in autumn leaves are the result of tannin, a chemical that exists in many leaves, especially oaks.) 

Sugar trapped in autumn leaves by the abscission layer is largely responsible for the vivid color. Some additional anthocyanins are also manufactured by sunlight acting on the trapped sugar. This is why the foliage is so sparkling after several bright fall days and more pastel during rainy spells.

To read the rest of the article and find out what brings the best fall foliage and where, click HERE

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