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In Living Color: Fall Leaves
Fall is the season when the leaves change colors from green to shades bright red, orange and yellow. This unit's lessons will take you on a "leafy" exploration of this colorful time of year!
As the summer days grow shorter and cooler, we prepare for fall, the common name for autumn season. Fall begins at the autumnal equinox, the time when the sun crosses the equator. In the Northern Hemisphere, north of the equator, fall usually begins on September 22 or 23 and lasts until mid December. In the Southern Hemisphere, south of the equator, autumn lasts from March until early June.
Why Leaves Change Colors
Fall colors occur due to chemical changes that happen in trees as the seasons move from summer to winter. Leaves contain cells that have a green pigment called chlorophyll. During the spring and summer, chlorophyll cells in leaves absorb sunlight and use this energy to convert carbon dioxide, a gas in the air, and water into carbohydrates, such as starch and sugar. Carbohydrates are the foods that trees and other plants need to grow.
In addition to green pigment from chlorophyll, leaves also contain yellow pigments from xanthophyll and orange pigments from carotene, the same chemicals that give colors to foods such as bananas and carrots. For much of the year, those colors are hidden by the large amounts of green pigment in leaves. In fall, fewer hours of sunlight and cooler temperatures cause leaves to gradually stop making food, the green color disappears and the yellow and orange hues become visible.
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Native American Legends About Fall |
Native Americans told many stories about the fall season. Below are two legends about why leaves change colors and fall off the trees.
Native Americans in North America held great respect for the bear. One legend tells of the slaying of the Great Bear by celestial hunters. The blood from the bear rained from the sky onto the forests, coloring the some of the leaves red. As the hunters cooked the bear, the fat from the fires splashed out of the kettle and onto the trees, coloring the other leaves yellow.
This ancient legend comes from the Cherokee nation. There was a time when only plants and animals lived on the Earth. The Great Spirit told the plants and animals that they would receive great powers if they could stay awake for seven days and seven nights. Only a few creatures fulfilled the request and were granted these gifts: eternal color and the power of night. Trees such as pine and cedar were allowed to stay green. Other trees had to shed their leaves and sleep during the winter. Animals such as owls and mountain lions were permitted to wander at night.
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During the fall, other chemical changes cause the formation of red and purple colors in leaves from anthocyanin pigments. These pigments are common in flowers and foods such as apples and grapes. The amount of pigment mixture determines the range of colors in the leaves.
Weather conditions -- amount of sunlight, temperature, and water -- play a significant factor in the intensity and length of fall colors. The vivid red colors need warm, sunny days and cool nights above freezing. Trees that are protected by shade are often yellow. An early frost and too little rain will reduce the depth of the colors.
Do All Trees Lose Their Leaves in Fall?
Some trees, commonly called evergreens, keep their leaves in the fall. The leaves on these trees are resistant to loss of water and cold temperatures. Some evergreens, such as pine and spruce trees, have long, thin needles for leaves. Some evergreens keep their individual leaves for two or more years! Many evergreens belong to a family of trees called conifers.
Deciduous trees, such as oaks and maples, growing in temperate climates shed their leaves in the fall.
Why Leaves Fall Off Trees
At the base of the stem of each leaf on a tree, there is a layer of cells called the abscission or separation layer. This layer is found at the point where the stem of a leaf is attached to a tree. During the summer, small tubes in the separation layer carry water into the leaf and food back to the tree. In the fall, this layer swells and makes a cork-like substance that cuts off the flow of water and food between the leaf and the tree. A seal forms between the leaf and the tree, gradually destroying the tissues that nourish the leaf. The separation layer forms a tear-line and soon, the leaf blows away or falls from the tree.
Learn More!
Resources about fall leaves
Online Sources
Fall Fun Online
Books
Ehlert, Lois, Red Leaf, Yellow Leaf, Harcourt Brace, 1991
Maas, Robert, When Autumn Comes, Owlet, 1992
Maestro, Betsy, Why do Leaves Change Color?, HarperTrophy, 1994
Robbins, Ken, Autumn Leaves, Scholastic trade, 1998
Schnur, Steven, Autumn: An Alphabet Acrostic, Clarion Books, 1997
Silverstein, Shel, The Giving Tree, Harpercollins Juvenile Books, 1986
Sohi, Morteza E., Look What I Did With A Leaf, Walker & Co, 1993
LESSON 1:
Identifying Fall Leaves
Concepts:
You will learn about ways to identify leaves and create a leaf scrapbook.
Lesson:
Complete the first two activities prior to a nature walk.
- Have students define and discuss the word deciduous from What's A Temperate Deciduous Forest Like?. Study the map from Where Are They Located? Ask students: Find the continent where we live. Do we live in temperate deciduous climate?
- Ask students: What kinds of leaves grow on the trees in our neighborhood? Study and discuss the drawings showing ways to identify leaves from these sites:
Have students scroll through the Autumn Leaf Scrapbook to view pictures of leaves. If you have a color printer, print the pictures from the list.
Take the students on a walk through a park, forest, or preserve in your area. Bring notebooks with you. Collect several different kinds of leaves. Have students note the characteristics of the leaves in their notes. Ask students to identify as many of the leaves as they can. Upon return, have students make a scrapbook of the leaves. You might use an old photo album with clear stick pages or have students make scrapbooks using different colored tagboard or construction paper, binder rings, markers, scissors and clear contact paper. Have students label each leaf with the following information: type of leaf, date found, location found.
Variation:
Have students arrange the leaves in their scrapbooks by a category; for example, by color, location, date or species.
Extension:
How much did students learn? Have students take an online quiz to review their knowledge of leaf identification.
Additional Resources
LESSON 2:
Autumn Poems
Concepts:
You will learn how about writing poetry with a fall theme.
Lesson:
You may want to complete these writing activities after a nature walk where the children have gathered fall leaves.
- Have the children study the poems The Leaves from the Scholastic website. Discuss rhyming words and have the children identify the rhyming words in each poem. Note the patterns in the poems. Have the children write short poems about fall leaves. Encourage creativity: Let them write the poems in patterns similar to falling leaves or in the shapes of leaves.
- Have the children write haikus about fall. A haiku is a poem with three lines in which the first line has five syllables, the second line has seven syllables and the third line has five syllables. Have the children read and discuss the following examples of haikus with fall themes written by students.
After discussion, have the children complete the activities from the Fall Haiku Lesson Plan.
Additional Resources
LESSON 3:
Fall Foliage Maps
Concepts:
You will learn about geography and fall foliage.
Lesson:
Where do leaves change in the United States? What are the best times to view fall colors in the United States? Have students study the Normal Peak Times for Fall Colors Map from The Weather Channel. If you have a color printer, print out the map.
Pose these questions:
- Which regions of the United States have the most fall color?
- Which regions have the least amount of fall color?
- Which regions have peak colors in September?
- Which regions have peak colors in November?
- Which states are missing on this map?
- Is our state or region on the map? If so, when is the peak leaf time for our state?
Print out an outline map of the United States. Have students label each state and list the states that have areas of fall color. Use the Normal Peak Times for Fall Colors Map for reference. Students may use our blank worksheet or a sheet of paper for their list.
Additional Resources
LESSON 4:
Photosynthesis Experiments
Concepts:
You will learn about photosynthesis and how this process affects leaves.
Lesson:
In this lesson, students will complete some experiments to help them learn the basic concepts of photosynthesis. While most of the experiments can be done with household materials, you may need to purchase a few items for the experiments geared for older students.
Projects To Do Together (Grades 3-12)
Have students learn how to separate colors in a green leaf and fall leaves using chromatography, and study how light affects color development in fall leaves.
Note: Adult supervision is required for these projects.
Photosynthesis (Grades 3-8)
Scroll down the page to the Activity Page for experiments and other hands-on activities.
Photosynthetic Pictures Are Worth More Than a Thousand Words (Grades 9-12)
Activity for high schools students to observe and examine how carbon dioxide, water, and light produce sugar and starch via photosynthesis.
Note: Adult supervision is required for this experiment.
Photosynthesis and Transpiration (Grades 6-8)
This simple experiment from The Educator's Reference Desk has students exploring the affect of light on plants.
LESSON 5:
Autumn Leaf Projects
Concepts:
You will use learn how to use common household materials and fall leaves to create art projects.
Lesson:
Have students gather some small, flat fall leaves in your community. Discuss the types of leaves they find. Let students use the materials and steps in the projects described below to create art projects with a fall theme. Enjoy the fun!
I. Autumn Windows
You will need to complete this project over two days.
Materials:
- parchment tracing paper --14-inches by 17-inches.
- spray laundry starch
- small, flat autumn leaves
- dried flower petals
- feathers and other fun flat things
- wooden sticks -- 9 to10 inches long and ¼-inch thick
- string cut into 18-inch lengths
- construction paper
Directions:
Day 1
- Fold the parchment paper in half lengthwise. Open the sheet.
- Spray the entire paper with laundry starch.
- Arrange the leaves, flower petals, feathers, etc. on one side of the fold line.
- Fold the paper over the design and press them together with a rolling pin.
- Let dry overnight.
Day 2
- Cut the construction paper into 7½ -inch by 3-inch strips. Fold the strips in half lengthwise.
- Place stick inside the fold with the ends sticking out. Glue the ends of the construction paper to the top of the project. Optional: Repeat this step to place a second stick at the bottom of the project.
- and glue one to the top and glue to the top of the project leaving room for the stick. Optional: Glue a second stick to the bottom.
- Tie a long piece of string to both ends of the stick.
- Use the string to hang the completed project in a window.
Variations:
- Make stained glass windows using colored tissue paper ripped up into small pieces. Overlap the pieces to blend colors. Crinkle the tissue for special effects.
- Trace some of the leaves you gathered on colored tissue paper. Cut out the leaf shapes. Overlap the shapes to blend the leaf colors.
II. Autumn Wreath
You will next two days to complete this project.
Materials needed:
- paper plates (with the centers cut out)
- autumn colored paint
- glue
- string
- autumn items from nature gathered by the class such as:
- colored leaves
- acorns
- small pine, cypress, or juniper cones
- straw flowers
- dried grasses
- nuts
- dried moss or lichens
Directions:
- Have the children paint their paper plates with autumn colors and let dry.
- Poke a hole in the paper plate, run a string through the hole and tie the string in a loop for hanging.
- Next, have the children glue on all the autumn treasures you've gathered together. Tell the children to glue the leaves and flatter items on first; then add the nuts, flowers and bulkier items.
- Let dry over night.
- Hang on a door or wall.
Try other neat fall leaf projects from the sites listed below.
Additional Resources
LESSON 6:
How Many Leaves Are On a Tree?
Concepts:
You will learn about estimating and leaves.
Lesson:
How many leaves are on a typical tree? Follow the steps in a math activity to estimate the number of leaves on one or more trees in your neighborhood.
Additional Resources
LESSON 7:
Fall Leaves Online
Concepts:
You will learn about technology and fall.
Lesson:
How about creating your own online fall collaborative project? Have students design a fall collaborative project to connect to homeschoolers in other cities, states or countries! Study the steps for creating such project at Steps to Developing a Collaborative Project .
Addtional Resources
LESSON 8:
Fall Leaves Vocabulary
Concepts:
You will learn about vocabulary words related to fall, leaves, and trees.
Lesson:
After studying the story at the beginning of this unit and the completing the activities, have students test their knowledge of vocabulary words on a worksheet. Check students answers with the answer key. As an extension activity, have students' practice spelling the words and later use the words as part of a test. You can use our test sheet or writing paper to test students.
Article by Louis Lewis, HLN Curriculum Development
Article © Homeschool Learning Network, All Rights Reserved.
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