Leaf Coloring 101
WHY DO THE COLORS CHANGE?
Growth and a chemical change account for fall's bright colors. About two weeks before the leaves change color, a cell layer forms at the base of each leaf. This stops the flow of moisture to the leaf. As a result, chlorophyll, which is what makes leaves green, is not renewed, so other colors can be seen. Depending on the chemical make-up of that tree, different colors will appear.
Yellow and orange, always present in leaves and previously masked by the green, come from carotenes and xanthophylls-the same pigments which occur in carrots and daffodils. Yellow is normally found in birches, white ash, basswood (also known as linden), maples, beeches, witch hazel, aspens, and hickories.
Anthocyanin causes red and purple in leaves-and in cranberries. The most striking reds are often the sugar and red maple, northern red oak, sumac, mountain ash, and tupelo. Tannins cause the brown leaves, often seen in oaks, beeches and speckled alders.
WHY DO THE COLORS CHANGE?
Growth and a chemical change account for fall's bright colors. About two weeks before the leaves change color, a cell layer forms at the base of each leaf. This stops the flow of moisture to the leaf. As a result, chlorophyll, which is what makes leaves green, is not renewed, so other colors can be seen. Depending on the chemical make-up of that tree, different colors will appear.
Yellow and orange, always present in leaves and previously masked by the green, come from carotenes and xanthophylls-the same pigments which occur in carrots and daffodils. Yellow is normally found in birches, white ash, basswood (also known as linden), maples, beeches, witch hazel, aspens, and hickories.
Anthocyanin causes red and purple in leaves-and in cranberries. The most striking reds are often the sugar and red maple, northern red oak, sumac, mountain ash, and tupelo. Tannins cause the brown leaves, often seen in oaks, beeches and speckled alders.