Lesson Plan
Why Do Leaves Change Color?
Students will be able to explain why leaves change colors in the fall by identifying the role of chlorophyll, sunlight, and seasonal changes.
Understanding why leaves change color helps students connect with the natural world, fostering curiosity and observation skills about seasonal transformations.
Audience
2nd Grade
Time
30 minutes
Approach
Interactive exploration and visual learning.
Materials
Smartboard or projector, Leaf Color Slides, Chlorophyll Painting Activity materials (white paper, washable paint in red, yellow, orange, green, paintbrushes, small cups for water), and Leaf Observation Journal
Prep
Gather Materials & Review Content
15 minutes
- Review the Leaf Color Slides to ensure familiarity with the content and flow.
* Gather all necessary materials for the Chlorophyll Painting Activity: white paper, washable paints (red, yellow, orange, green), paintbrushes, and small cups for water.
* Print copies of the Leaf Observation Journal for each student.
* Set up the projector/Smartboard for the slide presentation.
Step 1
Warm-Up: What Do You Notice?
5 minutes
- Begin by displaying the first slide of the Leaf Color Slides (title slide or a vibrant image of fall leaves).
* Ask students: "What do you notice about these leaves? What colors do you see?"
* Facilitate a brief discussion, encouraging students to share their observations and prior knowledge about fall leaves.
Step 2
Introducing Chlorophyll
10 minutes
- Use the Leaf Color Slides to introduce the concept of chlorophyll and its role in making leaves green.
* Explain how chlorophyll acts like a tiny chef, using sunlight to make food for the plant.
* Show slides demonstrating how chlorophyll breaks down as days get shorter and cooler, revealing other colors.
* Ask guiding questions: "What color does chlorophyll make leaves? What happens to chlorophyll when the weather gets cold?"
Step 3
Activity: Chlorophyll Painting
10 minutes
- Distribute materials for the Chlorophyll Painting Activity.
* Instruct students to paint a green leaf, then add other fall colors (red, yellow, orange) on top or around it to represent chlorophyll disappearing and other colors emerging.
* Explain that the green paint represents chlorophyll, and the other colors are like the hidden colors that appear when the green fades away.
* Circulate and provide support, asking students to describe their leaf and the colors they are using.
Step 4
Cool-Down: Reflect and Draw
5 minutes
- Have students complete the Leaf Observation Journal by drawing their favorite fall leaf color and writing one sentence about why leaves change color.
* Collect journals as an exit ticket.
* Conclude by asking students to share one new thing they learned about leaves today.
Slide Deck
Why Do Leaves Change Color?
Look at these beautiful leaves! What colors do you see? What do you notice about them?
Welcome students and introduce the topic. Ask open-ended questions about what they observe in the image.
The Green Machine: Chlorophyll
Most leaves are green! This is because of something called chlorophyll.
Chlorophyll is like a tiny chef inside the leaf that uses sunlight to make food for the tree. Yum!
Introduce chlorophyll as the green pigment. Explain its role in making food for the plant using sunlight.
Where Does the Green Go?
As summer ends and fall begins, the days get shorter and cooler.
The tree gets ready for winter, and the chlorophyll starts to disappear.
When the green chlorophyll goes away, other beautiful colors that were hiding in the leaf start to show!
Explain that as days get shorter and cooler, chlorophyll breaks down. This reveals other colors that were always there but hidden.
Red, Yellow, Orange!
Different leaves have different hidden colors. This is why we see so many amazing shades in the fall!
Can you name some of the colors you see in fall leaves?
Show examples of different fall colors and briefly discuss the pigments responsible (though not in too much detail for 2nd grade).
Fall Colors: A Summary
Chlorophyll makes leaves green.
Shorter, cooler days make chlorophyll disappear.
Hidden colors (like yellow, orange, and red) show through!
It's nature's beautiful show!
Summarize the key takeaways and transition to the activity.
Script
Leaf Color Script
Warm-Up: What Do You Notice? (5 minutes)
(Teacher displays the first slide of Leaf Color Slides - title slide or vibrant fall leaves image)
"Good morning, everyone! Look at this beautiful picture. What do you see? What colors jump out at you?"
"That's right, so many amazing colors! Who can tell me what time of year we usually see leaves like this?"
"Fantastic! Today, we're going to become leaf detectives and uncover the secret behind why leaves change into these brilliant colors in the fall!"
Introducing Chlorophyll (10 minutes)
(Teacher moves to Slide 2: "The Green Machine: Chlorophyll")
"Take a look at this leaf. What color is it mostly? Yes, green! Most leaves are green for most of the year. Do you know why? It's because of something super important inside the leaf called chlorophyll."
"Can everyone say 'chloh-ruh-fill'? Excellent!"
"Chlorophyll is like a tiny, magical chef inside every green leaf. Its job is to use the sunlight to make yummy food for the tree to grow big and strong. What a busy chef!"
(Teacher moves to Slide 3: "Where Does the Green Go?")
"But then, something changes. As summer starts to say goodbye, and fall breezes in, the days get a little shorter, and the weather gets a little cooler. The tree starts to get ready for a long winter nap."
"When the tree gets ready for winter, our tiny chlorophyll chef stops making food as much, and slowly, the chlorophyll starts to fade away, almost like magic!"
"Now, here's the cool part: all along, there were other colors hiding inside the leaf, but we couldn't see them because the green chlorophyll was so strong. But when the green goes away, poof! These hidden colors get their chance to shine!"
"So, what color does chlorophyll make leaves? And what happens to the chlorophyll when the weather gets cold and the days get shorter?"
(Teacher moves to Slide 4: "Red, Yellow, Orange!")
"That's right! When the green fades, we start to see all sorts of other colors, like bright yellows, fiery oranges, and deep reds! These colors were always there, just waiting for their turn to be seen."
"This is why every fall, our trees put on a spectacular color show for us! It's nature's way of getting ready for winter."
"Who can tell me some of the amazing fall colors we see when the green disappears?"
Activity: Chlorophyll Painting (10 minutes)
"Now it's your turn to be artists and scientists! We are going to do a Chlorophyll Painting Activity!"
"I am going to give each of you a piece of paper and some paints. First, I want you to paint a leaf green in the middle of your paper. This green represents the chlorophyll, working hard all summer."
"Once you have your green leaf, you can start adding other fall colors—like red, yellow, and orange—around or on top of your green leaf. Imagine the green fading away and these beautiful hidden colors starting to show through!"
"What colors are you using for your hidden leaf colors? What color did your leaf start as?"
(Circulate, assist, and encourage students. Provide positive feedback.)
Cool-Down: Reflect and Draw (5 minutes)
"Amazing work, leaf artists! Now, to wrap up our leaf detective work, you'll each get a Leaf Observation Journal."
"On the first page, I want you to draw your favorite fall leaf color that you learned about today. Then, below your drawing, write just one sentence about why leaves change color in the fall. Think about our 'green chef' and the hidden colors!"
(Collect journals as students finish.)
"Before you go, can one or two people share one new, amazing thing they learned about leaves today?"
"Wonderful! You are all fantastic leaf scientists! Give yourselves a round of applause!"
Activity
Chlorophyll Painting Activity
Objective: To visually represent the concept of chlorophyll fading and other leaf colors emerging.
Materials:
- White paper
- Washable paint: green, yellow, orange, red
- Paintbrushes
- Small cups for water
- Paper towels for dabbing brushes
Instructions:
-
Start Green: On your white paper, use the green paint to draw and color in the shape of a leaf. This green represents the chlorophyll that is busy making food for the tree all summer long.
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Add Hidden Colors: Once your green leaf is painted, imagine the green chlorophyll starting to fade away as fall arrives. Now, using your yellow, orange, and red paints, add these "hidden" colors to your leaf. You can paint them over the green, around the green, or in different sections of your leaf. Show how these beautiful colors start to appear!
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Explore and Create: Experiment with how the colors blend and layer. Think about what a real fall leaf looks like when it changes color.
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Share Your Art: When you are finished, be ready to share your colorful leaf and explain how your painting shows what happens to leaves in the fall!
Journal
My Fall Leaf Journal
Name: _____________________________
Draw Your Favorite Fall Leaf Color!
Draw a picture of your favorite fall leaf color that we learned about today. Make it vibrant and beautiful!
Why Do Leaves Change Color?
Write one sentence about why leaves change color in the fall.