Why the Leaves Change Color in Fall


As the days become shorter and the nights become cooler, Mother Nature begins to prepare herself for the long winter months. The leaves on trees transform from shades of green to a colorful palette of yellows, oranges, and reds before eventually falling off onto the ground. What some may not know, however, is that many of these autumn hues are there in the summer months too. We just can't see them underneath all that green.

Mother Nature's True Colors

Leaves are considered to be nature's food factories. They use chlorophyll to create food for the tree by helping to convert sunlight into sugars and starches. This chemical is also responsible for producing the green pigments you see in tree leaves throughout most of the year. As the days get shorter during the fall months, however, chlorophyll production slows down.

During this time, chlorophyll breaks down and the green color in leaves fade and then disappear. After it fades, yellow and orange colors are revealed. These hidden pigments, created from the chemical carotenoid, are present in the leaves the whole time, but cannot be seen through the dominating green color produced from chlorophyll.

Red and purple pigments, on the other hand, aren't typically created until the fall. Sunlight and the cooler weather at night cause anthocyanin chemicals to form, which produce red and purple in certain tree leaves. Trees exposed to more sunlight will have more red in their leaves than shaded trees.

The vivid colors of autumn leaves are influenced by sunlight, temperature, and soil moisture. As the weather gets colder and foliage breaks down, trees must live off the food produced during the warm months. Leaves lose their colorful pigments and eventually fall onto the ground. When winter ends and warm weather returns, however, new leaves form and the process repeats itself.



Color & Appearance Measurement Blogs

Light & Display Measurement Blogs