Visitor FAQs: Different colored leaves

One thing I love about my profession as an interpretive naturalist is that I never stop learning new things.  And it's often the visitors of the nature center where I work that ask the most interesting questions.  Below is my answer to a question a recent visitor asked.

Question:  Why do some trees and plants have different colored leaves?

 The majority of plants have leaves that are green during the summer months.  This is because the green pigment of chlorophyll, a plant fluid that aids in photosynthesis (food production), has a strong green pigment that often overpowers other colors within the plant.

Sometimes certain species or cultivates of plants produce leaves of varying colors during the growing season. Usually this is due to the fact that certain pigments in some species of plants can overpower the green pigment from chlorophyll.   For example, Japanese Red Maples (Acer palmatum) consistently have  dark red leaves, making this hardy tree a popular ornamental plant.  Sumac trees, which are frequently seen growing along roadsides and near ditches, sometimes have variegated leaves of red or yellow.

In the fall in temperate climate zones, many broad-leafed plants shed their leaves.  As they do this, the chlorophyll dissipates, exposing the true color of the foliage.

Occasionally, leaves might display different colors due to chlorosis, which can be caused by disease, nutrient deficiencies, pollution, lack of light, or other environmental stressors.  This is a serious problem that could lead to a plant's death.  It is difficult to tell which environmental stressors are causing chlorosis on a given plant species.

Figure 1:  Some plants, like this ornamental Photinia, have variegated leaves with pigments that overpower green chlorophyll.  


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