Why do leaves change color in the fall?


It’s a question we have all been asking since we were little- why do leaves go from green to red, to orange, or to yellow in the fall? Well, there are 3 factors that influence this spectacular change: 1. pigments in the leaf, 2. the decreasing length of the day and sunshine, and 3. weather. As our nights grow longer, days grow shorter, and the temperatures get cooler, a biochemical process is taking place in the leaves of deciduous trees.

Some Curiosities to Know:
Photosynthesis– when you break this word apart it means- “putting together with light,” since photo means light and synthesis means to put together. With the help of sunlight, leaves put together carbon dioxide and water to make sugar and oxygen.

So, let’s talk a little about pigments:
Chlorophyll gives leaves their green color. It is necessary for photosynthesis, as is light, carbon dioxide from the air, and water from the soil.
Carotenoid produces orange colors. You see this pigment in sugar maple and sassafras leaves and carrots and pumpkins.
Anthocyanin produces red, purple, and blue colors; they are water soluble which appear in the leaf cells’ watery liquid. You see this pigment in red maple, scarlet maple, oak, and red sumac. You also see it in fruits and veggies such as- grapes, red apples, blueberries, and strawberries.
Xanthophyll produces yellow color. You see this pigment in maples, beech, honey locust, and aspen leaves. This pigment also gives squash and corn their yellow coloring.

During the warm months and longer days of spring and summer chlorophyll is continually being produced and causing the leaves to be green. When the days become shorter during the autumn months, the production of chlorophyll slows down and eventually stops completely; therefore putting on a display of the beautiful carotenoid, xanthophyll, and anthocyanin pigments that make autumn.

Now to extract the pigments-

You Need:
 *leaves of many colors, use colored fall leaves as well, 4 or 5 of each color
*glass jars (one for each color)
*rubbing alcohol
*small bowl of hot water
*filter paper (white coffee paper or a tea bag)
*butter knife

Step 1: Gather the leaves and rip them into small pieces. Place same colors in separate jars.


Step 2: Add rubbing alcohol into the jar until it just covers the leaves.


Step 3: With a butter knife mash and bruise the leaves.


Step 4: (optional)  Boil some water and place in a bowl, add your jar with the leaves and alcohol. This will speed up the pigment extraction a little bit, but I don’t feel the results are fast enough to make it necessary.


Step 5: Place the filter paper into the leaf mixture, leaving the top to hang over the top of the jar.


Step 6: Wait an hour and you will start seeing the pigments make an appearance on the filter paper. Wait 24 hours for the best results.


Wow, look at the anthocyanin extracted from the red maple leaves! It is so pretty!


Stay Curious,