Why leaves change colour
The dazzling palette of fall foliage is a signal that our deciduous trees, shrubs and plants are getting ready for winter, a rather colourful survival strategy. Throughout the growing season, they have been setting seeds and making food for winter storage. The leaves of summer, green because of chlorophyll they contain, have been utilizing the sunlight, altering water and carbon dioxide in the making of food. The intensity of the colour depends on the amount of sunlight the leaves receive. Sunny days and cool nights will release a more dramatic display and variety of colour.