“I don’t need you anymore for the season,” said the tree to the leaf.
With the weather getting cooler and days getting shorter deciduous trees stop producing chlorophyll, the molecule that absorbs sunlight and uses its energy for photosynthesis, in preparation for winter.
During fall, certain hormones trigger the process known as abscission whereby the leaf stem cuts off the leaf from the tree. These “abscission cells’ reabsorb valuable nutrients right before winter and gently pushes the leaves away from the stem.
So the reason why leaves fall isn’t that it’s windy, the tree kicks out the leaves in preparation for dormancy so that new leaves can emerge in the Spring.