Why Do Leaves Fall From Trees & How Many Hit the Ground?

We see the changing of leaves late in the summer and, of course, as fall arrives we see many more changes in those leaf colors. Eventually they start falling off the trees. Who makes the executive decision of the leaves detaching themselves from the tree?

Your logical answer for the leaves falling may be because it's turning colder. That's what I always thought. Maybe it's just the wind doing it's job to clean out the branches. Well, you're wrong on both accounts.

The official name for the third season of four is Autumn. Now I imagine term "Fall" had to do something with the leaves falling from the trees. You know, they go through a transformation of the colors, i.e. from green to orange and/or yellow, eventually changing to their boring brown color.

Now there is a scientific reason. I'm not going to bore you with a bunch scientific mumbo jumbo. So here's an easy explanation. According to the Missouri Botanical Garden's Peter Raven:

The wind doesn't gently pull leaves off trees. Trees are more proactive than that. They throw their leaves off. Instead of calling this season "The Fall," if trees could talk they'd call this the "Get Off Me" season.

In a story from NPR, changes take place as a hormone is sent to the leaves that basically tell the leaves to get out of Dodge!

And if you're wondering what's the average number of leaves that fall from a tree every year, an average oak tree will have 254,480 leaves. How many of those will fall? Who knows but even it's 80% of that number, you're still looking at approximately 203,000 leaves. That's a lot raking and bagging!