Why do leaves change color in Fall?

As summer ends and autumn comes, the days get shorter. A busy year making flowers and seeds, the trees need their rest and so get ready for winter. Thus, the trees begin to shut down their food-making factories, the green chlorophyll. As it disappears from the leaves, the yellow is left behind briefly until it too is gone and all that is left is the brown, the remnants of a glorious summer and beautiful fall.

 

Fall leaves, Mulberry tree

Kansas Paw Paw

Pin Oak, Kansas

What makes the bright reds in Maple trees? These colors and the deep purples we see are glucose trapped in the leaves after photosynthesis stops. Autumn daylight and cool nights combine to produce these brilliant colors.

Maple tree, Kansas