One thing that I really enjoy about the fall season is the colour of the leaves. Fortunately, I live in Southern Ontario where I actually get to see the leaves change colour before they fall =). I don’t know why, but it seems like this year the colours are particularly nice and vibrant. A couple weeks ago, I took a roadtrip to Montreal and on the way there we passed through many stretches of red, yellow, and orange. It was kind of distracting since I was driving, but t’was breathtaking!

As I was marveling at the landscape, I wondered why the leaves change colours and what triggers them to change.

Well, allow me to explain… [Disclaimer: This is an oversimplification. I am in no way an expert on trees.] We all know that plants go through a process called photosynthesis to convert water, CO2 and sunlight into glucose and oxygen. We also know that photosynthesis relies on a chemical called chlorophyll, this is what gives the leaves their green colour.

Now, in the winter, there is not enough sunlight because the days are short. So, plants basically pack it in and decide to store up for the winter and stop producing glucose and oxygen. In turn, the chlorophyll is not needed for photosynthesis. Then, out comes the nice red, yellow, and orange colours!

Wonderful, ain’t it? Now you know why all the trees change in the fall.