What is it With Trees?

Well, it has happened again. As surely as seasons change the most intriguing of events takes place. I marvel each spring and fall at this happening. I have never understood what it is with trees. Have you noticed that in the last few days they have started putting on their clothes?? I discussed this with my elementary students each year. What is it with trees that they put on their clothes in the Spring when the weather starts to heat up and then things get really warm? Then here they are all fully clothed and it is very, very hot outside. But in about five months or so they start taking off their clothes and throwing them on the ground. Shortly after that it starts to get cool and finally quite cold. It seems to me that trees are so mixed up on this how to dress appropriately thing.