I always get excited in fall as the nights grow colder and the days shorten, as these two ingredients are part of the recipe for one of Mother Nature's most splendid spectacles: fall foliage in Vermont. 

Have you ever wondered what makes our trees turn from brilliant greens to dazzling reds, oranges, and purples? Leaves contain chlorophyll, the chemical that gives plants their green color. Chlorophyll is used in photosynthesis, the process green plants use to make food. Plants use sunlight to turn water and carbon dioxide into oxygen and glucose. Plants use glucose, a type of sugar, as food for energy and as a building block for growing.  

During winter, there is not enough light or water for photosynthesis to occur. As the trees shut down for the winter, the bright green chlorophyll also disappears from the leaves, and small amounts of other colors like reds and oranges start to emerge.  

These other colors have always been in the leaves-we just can't see them in the summer, because the green chlorophyll covers them. The bright red and purple fall foliage colors come from anthocyanin pigments. These pigments can be found in many other plants, like beets, red apples, and flowers like violets. Orange foliage is created by carotene, the same pigment that makes carrots orange, and yellows are formed by xanthophyll, which is also found in egg yolks.  

Complete the following experiment to reveal the hidden colors in a green leaf. Can you predict what color the leaves in your yard will be this fall?

Leaf Chromatography Experiment 

What You Will Need:

Coffee filter

Scissors

Green leaves

Coin

Rubbing alcohol

Jar

Pencil

Tape

Foil

Step 1: Cut a 1-inch strip from a coffee filter.

Step 2: Use a pencil and ruler to mark a line about 1 inch above one end of the coffee filter strip.

Step 3: Place a green leaf on top of the paper, and use the coin to rub the leaf on top of the pencil line. Make sure that the pigment line is heavy.

Step 4: Pour a 1/2-inch layer of rubbing alcohol into the bottom of a jar.

Step 5: Tape your paper strip to the middle of a pencil and hang it so that the very tip of the strip touches the alcohol. (The colored line of leaf pigment should not touch the alcohol.)

Step 6: Lay a piece of foil over the top of the jar to keep the alcohol from evaporating.

Step 7: Observe the pigment line as the rubbing alcohol absorbs and draws the pigment up the paper. If the leaf contains different pigments, they will separate out and create multiple color bands along the paper.

Step 8: Before the alcohol soaks all the way up the paper, remove it from the jar, and allow the paper to dry.

The finished paper is called a chromatograph. How many colors do you see? Once the leaves in your yard start to change color, compare your chromatograph with the real leaves to see if your color predictions were correct.

Enjoy the splendor of fall and explore your world every day!

The Nature Museum at Grafton relies on the generosity of volunteers and donors. Community involvement allows us to offer a breadth and depth of programming that vastly outmatches our size. If you would like to offer your time to the Museum--whether your talent is for painting porches, greeting visitors to the Museum on the weekend, or identifying benthic macroinvertebrates--you can let us know by submitting the form on our online volunteer page or giving us a call at (802) 843-2111. Thanks! 

Speaking of benthic macroinvertebrates, thank you to David Eastman, licensed educator, homeschooling father, and board member of The Greater Upper Valley chapter of Trout Unlimited, for volunteering to lead our September homeschool program on river fish and river insects.

Alex and Antonia

Thanks to Mary Thompson, who helped out with our Grafton Elementary School summer nature program for all four weeks! A big thanks, too, to our summer preschool camp assistants, Alex Harris and Antonia Dufort, who helped to lead our preschoolers through meadow, forest, and pond habitats.

Thanks to the Vermont Beekeepers' Association for sending George Bailey and Clark Johnson of Champlain Valley Apiaries and Vermont Bee Removal to collect our swarm of honeybees. Champlain Valley Apiaries also
donated a super and frames for our outdoor bee exhibit. Thanks to longtime Nature Museum friend Dick Warren for his donation of bees. The Nature Museum still has plenty of bees in our indoor exhibit.