Why do leaves change color?

Why Fall Leaves Change Color Plus An Experiment For You!

Okay, give me 3 reasons why leaves change color in the fall?

C’mon, real quick and no Googling it!

I remember in grade school learning something about how the shorter days of light in the fall was the reason and heard the stories about colder temperatures. Each year, we speculate on when the leaves will begin changing and will it be a good season of color or not – exactly what does influence that?

Here, is another thing that has stumped me, what trees give out what color?

And, is there an experiment you can do in the summer to determine what their color will be in the fall? That sounds like a fun workshop we should do for families staying with us!

Turns out you can!

So in believing that blogs should be this journey where we explore together, I decided to investigate this. If you have info on why leaves change color or know of on-line resources let us know!

As I was doing research, I came across a resource I was familiar with during my days working on sustainable development in the Park. “SUNY ESF” short for the state college system in New York, this one for Environmental Science and Forestry.

In an article entitled, appropriately enough, “Why Leaves Change Color,” (https://www.esf.edu/pubprog/brochure/leaves/leaves.htm.

Text prepared by Carl E. Palm, Jr. ), it turns out my memory was correct, and light and temperature do play a role. Calling the spring and summer a food “factory” produced through a tree’s leaves, they are green due to chlorophyll. We have all heard about the importance of mother nature absorbing our carbon dioxide.

Does it happen to you too where subjects you found boring in high school, are now fascinating? Is that a sign of maturity or old age when things right in front of you, that have been going on since you were a kid, suddenly become interesting, even mysterious and glorious?

Maybe it is not a an old age thing, as I am amazed at all the texts my kids do with each other all day about simple stuff like driving conditions, the weather and yet they are stumped when I ask them why do leaves turn color or, do they know each other’s class schedule? How am I supposed to plan Thanksgiving?

According to the ESF article, the fall colors we see now, are already in the leaves in pigments called “carotenes” and “xanthophyll” which “give  the orange color to a carrot.” Carotenes and “carrots?” Is there a word connection there?! 

Anyways, they are dominated by the green producing chlorophyll cells of a leaf. In the fall as the days get shorter and colder, the food factory “leaves” (okay, bad pun) or shuts down. You know, sort of what happens this time of year when the Northeast population “leaves” to sunny Florida. 

As this cycle breaks down, all the colors get mixed up. It’s like Chef Cathy’s blender with her fall blueberries found on the property that she mixes in with her famous muffins to create different shades of hues. Depending on the tree, different blender action gives off various colors. Some I do know, like  sugar maple is orange, birch a yellow, oak is brown.

Here is what I didn’t know.

There is a whole lot more going on. For example the ESF article points out why do leaves eventually “fall” (I can’t help myself)? Additional cells arrive on the scene and “gradually severs the tissues that support the leaf” causing it to…you got it, “fall.”

The magic isn’t done, as the tree performs surgery on itself, covering up the area where the leaf was attached as it awaits the cold winter before it begins the cycle again. Talk about turning over a new leaf.

And yes, you can predict how the foliage season will come to light (I couldn’t resist that one either). Weather does play a role on what you will see and how spectacular it is. In an article, “Using Indicators Determining Great Autumn Tree Color” by Steve Nix (https://www.thoughtco.com/predicting-fall-color-autumn-leaf-display-1342825 Predicting Fall Color and Autumn Leaf Display), too much of a good thing is bad. “The more leaves attached to trees entering the color season means more to look at. Droughty summer weather conditions can limit that volume but a wet summer can set up disease and insects.”

The ESF article points out that frost brings out the color but if it happens too early, it dampens the parade. Rain, as it does for the vibrance of our gardens (as long as it is not too much!) brings out their true colors. Perhaps nature’s way of reminding us when things are rainy, true character comes out.

But, here is a cool thing and I want to do this next summer as a fun workshop. During the height of the green colors, you can tell what color they will be in the fall – and even what kind of a foliage season it will be! In a process called chromatography, you can break down or separate the pigments in a leaf like nature does in the fall.

Now, I don’t want to give it all away now, so as to save the surprise for your summer visit, but it is amazing on how simple it seems to be. I haven’t done it either but looking forward to trying. In the meantime, you might want to get some kind of glass container, rubbing alcohol and filter paper! And then you can be in our summer newsletter telling folks about your fall foliage predictions!