Leaf it to Me!
Autumn officially arrived on Sunday, September 22nd. In my neck of the woods, the temperatures dropped and we had a brief downpour…just enough rain to announce that FALL is here.
At the end of this week, I leave for my annual “pilgrimage” to the north woods of Michigan’s Upper Peninsula. I’m looking forward to seeing the incredible autumn colors in the forest. But what makes leaves change from green to yellows, reds, browns, and purples?
It all has to do with photosynthesis—how trees make their food using sunlight and a pigment in their leaves called chlorophyll. It’s the chlorophyll that gives leaves their green color. As temperatures drop and the days become shorter, trees stop making food and the amount of chlorophyll inside of leaves decreases. With less chlorophyll, the other colors in leaves (orange and yellow) become visible. These colors were in the leaves all summer, but the green color of the chlorophyll covered them up. When the chlorophyll leaves, the leaves show their other colors.
Red, purple, and brown colors are the result of other chemical reactions that occur inside leaves when the temperature drops—leftover food (glucose) in leaves causes red and purple colors, and waste products in leaves cause a brown color.
Inside: Discover the Hidden Colors
See the hidden colors in green leaves by doing a simple experiment from Home Science Tools. Using just a few ingredients, your students can separate ALL the colors in a green leaf. Although it’s simple enough for elementary students, even my middle school kids had liked seeing the results from this experiment.
Collect an assortment of leaves and other natural objects from outside. Then use the whimsical illustrations in Leaf Man, written by Lois Elhert, to inspire your students to make their own leaf collages of animals and people. Both young children and older students enjoy using their creativity in this creative activity.
More Facts and Fun with Leaves
- Find out more about photosynthesis and chlorophyll at the Real Trees 4 Kids.
- Find lots of ideas for inside and outside leaf activities and projects at Kid Activities.
- Get directions for writing autumn acrostic poems at Teacher Vision.
F alling temperatures
A utumn activities
L osing leaves
L eaving summer behind