Everyone knows fall is the season where the leaves turn yellow/orange, dry out, and fall off the tree branches. Do you know why?
I have never known what causes this natural process, but like most, I assumed it was the cold weather that dries out the leaves and as the wind blows the leaves fall, right? Wrong.
According to an article I found on NPR.com, trees have a lot more influence in the process of the leaves falling off. In this article they did an interview with Peter Raven, the president of the Missouri Botanical Gardens. He mentioned that the leaves don’t just fall off the trees, the trees actually throw off their leaves.
The explanation behind this is during this time of year when the weather changes, a hormone is triggered in leaf falling trees that sends a chemical message to each leaf letting them know it is time to part. Once the message is received, little cells appear in the part where the leaf meets the stem. These are called “abscission cells” sharing the same root word as scissors, they serve the same function, of making a cut.
After this, it takes a few days or weeks for these cells to form a thin bumpy line along the leaf’s edge that slowly pushes the leaf away from the stem. Once the leaves are at the border of falling off the wind often finishes the job.
Why is it that the leaves fall off? Raven explains that the function of the leaf is to produce the food the tree needs to thrive and reproduce. When their food production slows down in the fall, the tree then decides whether or not to keep the leaves it no longer needs.
In cases when the tree decides to keep their leaves, during warm winter days some of these leaves will photosynthesize and when the weather cools back down, they freeze and die. Later as the spring comes, the dead leaves no longer produce food for the tree and the tree dies as well. Therefore it ends up being safer for the trees to get rid of their leaves and grow new ones in the spring.
Grow your own leaf falling tree, using our Deep Drip Watering Stakes. Deep Drip allows you efficiently and effectively water your trees and plants conserving up to 50% of your outdoor water use. The deep watering of the stakes also help establish deeper roots for a healthier and sturdier tree!
Sources:
http://www.npr.org/templates/story/story.php?storyId=114288700
