I am a Christian. I was an 8th-grade American History teacher. I am currently a freelance writer, public speaker, & homeschooling mom of 9.
Play a photosynthesis relay race, create an edible leaf structure, act out the parts of a tree, examine and classify tree leaves and use them to identify trees, and more in this fun, hands-on lesson on roots, stems, leaves, and trees! This is part 3 of a 4 part hands-on unit on Plants. This lesson is geared toward 2nd-3rd grade level children and their siblings. I created this to do with a weekly homeschool co-op which meets each week for 2 1/2 hours. Use this fun lesson with your class, family, after school program, camp, or co-op!
Introduction to Leaves
1. Pray. Read and discuss Psalm 1:1-3.
2. Place white carnation and/or celery in water generously colored with food dye. (Blue and green both work well.)
- Cut the stems just before placing them in cold water.
- It takes about 30 minutes for a short stalk of celery to begin showing dye in its leaves. It takes about 2 hours for the dye to show up a little bit in the flower petals if you have very short stems (about 1 inch long).
YOU WILL NEED: celery and/or white flowers (like carnations) and a bowl or cup of water with a generous amount of food dye
3. Briefly talk about transpiration.
- Show the plastic bag. Other than air, it's empty isn't it? What do you think will happen if we attach this bag to this leaf and leave it here?
- Cover a leaf on a tree or other plant with a clear plastic bag and tightly close the bag using a clothespin, rubber band, or tape. Make sure it's in a sunny spot.
- If the tree or plant is indoors, move it to a sunny spot. Continue on with the lesson.
- (It takes about 30 minutes for water droplets to show well.)
YOU WILL NEED: a tree or other plant, a clear plastic bag such as a sandwich bag, & a clothespin, rubber band, or tape
4. (Optional) While outside, pull up weeds and grass, making sure to include the roots.
5. Using the complete plants (with roots) pulled up from outside or plants brought to class, allow children to study the roots using magnifying glasses. What do you notice about the roots?
As they observe the root systems, briefly mention:
- Usually (not always): Most dicots have taproots (1 main root) & monocots have fibrous roots (lots of roots growing in many directions & wider rather than deeper). [Show examples]
- Why are roots important? (Allow students to answer) Root system anchors the plant in the soil, absorbs water & minerals for plant growth, & stores food
- Some plants like strawberries reproduce not by flowers but by vegetative reproduction. Their roots spread out to form new plants.
- The root cap (made of dead cells) protects new cells as they push through soil to lengthen root. Root tips are the strongest part of the root. They can lift houses. They upset sidewalks. If you’ve been on an uneven sidewalk with cracks, roots are probably to blame.
- Roots can grow long to get to water. The roots of a fig tree in South Africa grew 393 feet in order to get water! (That’s the length of a 36 story building!)
- Some roots grow above the ground like the ones for a banyan tree, which have roots hanging down from its branches in addition to the ones underground.
- [Show examples or pictures of bulbs or tubers.] Bulbs & tubers are not roots. Roots grow out of the bottom of a bulb. A bulb is made of special leaves & a short stem & is like a seed.
YOU WILL NEED: plants with roots (such as weeds and grass -- try to include one with a tap root like a wild flower & one with fibrous roots like grass), magnifying glasses, paper towels or table covers (to minimize the dirt mess), and examples or pictures of bulbs or tubers
Roots & Osmosis
6. Root hairs kind of look fuzzy like fur. Can you find some?
- Root hairs do most of the work, absorbing water & nutrients. Each root hair lives for about 6 weeks & then dies and is replaced.
- The root hairs absorb nutrients & water through osmosis, which is a continual movement of water from solution of higher water content through semipermeable membrane into solution of lower water content.
- Demonstrate osmosis by placing a piece of paper towel next to a small puddle of water.
YOU WILL NEED: water and paper towels
Being Rooted in the Word
7. Talk about being rooted in the word. Colossians 2:6-7 says, "So then, just as you received Christ Jesus as Lord, continue to live your lives in him, rooted and built up in him, strengthened in the faith as you were taught, and overflowing with thankfulness." What does it mean to be rooted in Jesus?
8. Allow children to study the stems of the plants using a magnifying glass. Have them break them open and look inside. What do they notice?
- What gives you your shape & allows you to move? (Skeleton & muscles; backbone) A plant needs to move too, lifting their bodies off the ground & giving them form.
- Plants have stems that contain tubes called a vascular system, like our veins & arteries. The vascular tubes carry fluids through the plant.
- Are all your stems the same? No, some are hard & woody and some are soft & green.
YOU WILL NEED: plants used above and magnifying glasses
Xylem & Phloem
9. Have students wash or sanitize their hands and then let them munch on a piece of celery. What do you they notice about the celery?
YOU WILL NEED: celery sticks for eating
10. Pass around the pieces of celery that were placed in water dyed with food coloring. How did the blue dye get into the leaves of the celery plant?
11. Xylem & Phloem
- Show a bundle of 2 different colors of straws banded together. One color represent xylem tubes and one color represents phloem tubes.
- There are 2 types of vascular tubes. Celery has lots of xylem tubes. Xylem tubes carry water & nutrients from root hairs to the leaves where water is used in photosynthesis or released through stomata. (Stomata are like tiny mouths or holes that cover a leaf.) In the xylem tubes, water zips up through the plant from the roots.
- Plants also need sugar to survive. They make their own sugar inside the leaf. The leaf takes water from the roots that came up through the xylem & combines it with light from the sun and carbon dioxide from the air to make sugar for the plant and oxygen for us and for animals. It sends sugar down from the leaves. The sugar runs throughout the entire plant’s phloem tubes to feed it. Sugar flows down through the phloem from the leaves.
YOU WILL NEED: a bundle of 2 different colors of straws bundled together using a rubber band
12. Dramatize transpiration.
- Ahead of time tape a piece of masking tape to the floor. Write "stomata" on it. Add other pieces of masking tape to the floor as a visual reminder that leaves have lots of stomata, not just one. If desired, place a sheet in the middle to be the leaf.
- In the xylem tubes, water zips up through the plant from the roots. Xylem tubes carry water & nutrients from root hairs to the leaves where water is used in photosynthesis or released through stomata. What are stomata? (Stomata are like tiny mouths or holes that cover a leaf.)
- The water gets pulled through a plant by a process call transpiration.
- (We did this in groups of 5.) Children will stand in a line with their hands on the shoulder of the child in front of them. Each child is a water molecule.
- The child in the front of the line will walk up to the stomata opening (the line on the floor) and will jump out of the leaf while yelling, "Evaporation." The water molecule evaporates up into the sky.
- As the front child jumps out through the stomata, that pulls the next child/water molecule. That child does the same through. jumping through the stomata while calling "evaporation."
- Repeat until everyone has done this.
- Review what you just did with transpiration. As a water molecule flies up into the sky out of the stomata, another water molecule must replace it. It pulls another one from down in the root system. This continues on.
YOU WILL NEED: masking tape, something to write with, & a sheet (optional)
13. Check on the bags that are over the leaves that you started at the beginning of class.
- Can you see any water in them?
- Where did the water come from? (the leaves) What part of the leave did the water come from? (stomata) What do we call this process? (transpiration)
14. If you're not limited by time, take a walk outside and have the children each collect 5-10 leaves from different trees. Otherwise, pass out tree leaves you've brought from home.
- Have the children study the leaves using their magnifying glasses. What do they notice?
- Divide the children into groups of 5 and have them sort their leaves into 2-3 groups. Why did they group them like they did?
YOU WILL NEED: 5-10 tree leaves per child (brought by the children or collected from outside)
15. Trees can be identified by their leaves using various traits. [Show examples using real leaves or pictures of leaves.]
- Leaf edges: smooth, toothed, sinuate, pinnated lobed, or palmated lobed
- Leaf shapes: linear, ovate, oblong, rounded, spatulate, obcordate, deltoid, or reniform
- Leaf veins: parallel, palmated, or pinnate
YOU WILL NEED: various types of leaves with different traits or pictures of them
16. (Optional) If you're not limited by time, follow along with this video on YouTube to draw 16 basic leaf shapes. It takes about 20 minutes.
17. Select one leaf from the group and identify it using the leaf traits and a tree guide. If you are not limited by time, give each child or pair of children a tree guide and have them try to identify a leaf from their pile. (Younger children required assistance with this. I would turn to the page or pages with that type of tree and tell them to locate it on the page or group of pages.)
YOU WILL NEED: leaves from above and tree guides
Angiosperms & Gymnosperms
18. Pass out pine needles.
- Is this pine needle a leaf. Why or why not?
- Compare a leaf with a pine needle.
- Briefly discuss the difference between gymnosperms and angiosperms (needles vs. leaves, coverless seeds vs. fruit, & no flowers vs. flowers).
YOU WILL NEED: pine needles
Pine Needle Tea
19. (Optional) If you live in an area with an abundant amount of pine trees, make pine needle tea.
- Place a large amount of pine needles in a pot of boiling water. (You can cut the pine needles of desired.)
- Cover the pot and let the pine needles seep in the water for at least 20 minutes.
- Drain the tea using a sieve or colander to remove the pine needles.
- Add sugar.
- Pine needles are very high in Vitamin C and this tea tastes citrusy.
YOU WILL NEED: pine needles, pot of water, colander or sieve, & sugar
Cellular Respiration & Photosynthesis
20. Cellular Respiration: We’re not done talking about leaves. Leaves not only release water in transpiration. They also use and give off air in a process called cellular respiration.
- Take a deep breath. You’re breathing in a gas called oxygen. Now breath out. You’re breathing out a gas called carbon dioxide. Animals do the same thing. They breathe in oxygen & breath out carbon dioxide.
- God created plants to “trade” air with us. Plants breathe too! Can you guess what they breathe in? Carbon dioxide, our waste gas. Can you guess what they breath out? Oxygen, the gas we humans and also animals need to breath.
21. Discuss photosynthesis
- Earlier we mentioned that stems contain 2 types of vascular tubes. [Show the straws again.] Which type of tube sucks up water from the roots and has it flow into the rest of the plant. (xylem)
- Who remembers the name of the other type of tube that transports the sugar or glucose from the leaves to the rest of the plant? (phloem)
- Plants need sugar to survive. They make their own sugar inside the leaf. The leaf takes water from the roots & combines it with light from the sun and carbon dioxide from the air to make sugar for the plant and oxygen for us and for animals. It sends sugar down from the leaves & the sugar runs throughout the entire plant’s phloem to feed it.
- Who’s had maple syrup on your pancakes? The real maple syrup is the sugar from a maple tree.
- They do this all day long while the sun is shining and then the stomata close & the leaves rest once the sun goes down.
22. Play the Photosynthesis Relay Race found at www.ellenjmchenry.com to review the formula for photosynthesis. Teams will race each other to complete the process of photosynthesis. They will place cards with water and carbon dioxide into the "in" envelope on a leaf and shine a flashlight on it and then will remove cards for oxygen, glucose, and water from the "out" envelope on the leaf.
YOU WILL NEED: at least 1 piece of green construction paper each cut into the shape of a leaf with 2 small envelopes glued to it, at least 1 flashlight, & free pattern pieces found at www.ellenjmchenry.com
Trees: Fruits and Nuts
23. What are some of the products we use from trees?
- Some of our favorite products are ones that we can eat such as fruit, nuts, and chocolate (cocoa powder).
- Make Tree Nut & Fruit Balls by following some of the recipe found at www.joyofbaking.com: In a food processor, blend together 1 cup of toasted tree nuts (such as pecans and/or walnuts), 2 cups of any combination of dried fruit (pitted dates, dried cherries, dried figs, pitted prunes, dried cranberries, and/or chopped dried apricots), and 2 tablespoons orange juice concentrate. Have the children roll the mixture into walnut-sized balls and roll the balls in cocoa powder or crushed pecans or walnuts. Place the balls in the refrigerator until you are ready to serve them.
YOU WILL NEED: food processor, measuring cups, 1 Tablespoon measuring spoons, 1 cup of toasted nuts (such as pecans and/or walnuts), 2 cups of any combination of dried fruit (pitted dates, dried cherries, dried figs, pitted prunes, dried cranberries, and/or chopped dried apricots), 2 tablespoons orange juice concentrate, 1/4 cup cocoa powder, 1/2 cup crushed and toasted pecans or walnuts, and 3 plates
YOU WILL NEED: Tell Me, Tree by Gail Gibbons or other book on tree parts
25. Direct children to act out each of the parts of a tree and their functions. (This activity originally came from Ranger Rick's Naturescope book Trees Are Terrific.) Children will work together to form the heartwood, taproot, lateral roots, sapwoods, cambium, phloem, & outer bark. (A similar activity can be found at gen.uga.edu). If you have a smaller group of children, have the children act out the root structure first and then act out the trunk structure separately. Have children act out the following parts and describe what that part does as you assign the part:
- Heartwood: Like the backbone of a person, it's the Inner core of the tree, giving it its strength, & holding the trunk upright so its leaves can get plenty of sunlight. For the first few years, it is alive xylem, but its tubes eventually get blocked with resin and pith, and it dies. -->The heartwood child should stand up straight, show his/her muscles to show s/he is strong, and then cross his/her arms together. Repeat, "I support!"
- Taproot: Long, large root or roots that get water & nutrients from the ground & anchor the tree in place. Taproots can reach as far down under the ground as the trunk of the tree stands above the ground.(Some trees like redwoods do not have taproots.) -->The taproot child should sit on the feet of the heartwood child to show that it anchors the tree. Pretend to suck up water by making a slurping sound.
- Lateral Roots: Lots and lots of smaller roots with even tinier rootlets which look like threads or hair. A tree can have millions of rootlets, many of which lie closer to the top of the soil and can immediately soak up water from the rain. All the roots work together to get water & nutrients from the ground & anchor the tree in place. They grow in the direction of water sources.
- Large taproots and lateral roots branch into smaller and smaller roots. --> The lateral root child or children should lie down with their feet toward the taproot. If the person has long hair, have her spread it out on the ground like rootlets. Pretend to suck up water by making a slurping sound.
- Heartwood: (Should already be standing)
- Sapwood/Xylem: Like a bunch of straws or pipes, the sapwood draws up water & minerals from the roots to all the branches and leaves and other parts of the tree, and it stores the nutrients. --> The sapwood child or children should hold hands to form a circle around the heartwood. Tell them to lift up their arms from the ground where the roots are and say, "Water and nutrients coming up!"
- Cambium: Can only be seen using a microscope because it's only 1-2 cells thick. It's where new layers are added to the sapwood and is the part of the tree that is growing outward to make the tree thicker. -->The cambium child or children should hold hands to form a circle around the sapwood and repeat, "We make new cells to grow outward."
- Phloem: Transports food (sap) created by the leaves to the rest of the tree The phloem acts as a food supply line from the leaves to the rest of the tree. If a tree's phloem was cut all the way around, the tree would mostly likely die because it wouldn't be able to get food. -->The phloem child or children should form a circle around the cambium, holding their fingers upward as if they were leaves. They should then lower their arms to signify them taking the nutrients from the leaves and spreading it to the rest of the tree. They can repeat, "We bring the food from the leaves to the rest of the tree."
- Outer bark: Like skin on a person, the outer bark protects the tree from bugs, diseases, and fungi. It also keeps the tree from drying out. You also Humans can damage you if they pull you away from the tree. As you get older you crack and stretch. -->The outer bark child or children should hold hands to form a circle around the phloem and repeat, "We protect!"
26. After the children have acted out their roles, review each of the parts and their functions.
Reading Tree Rings
27. Use a tree cookie (a slice of a tree trunk that shows the rings) to briefly discuss how tree rings can tell the age and history of a tree. If you are not able to get a tree cookie, you can search on-line for a free worksheet showing distinctive tree rings. Have children count the rings on their tree cookie or on the worksheet to determine the age of the tree. Point out the significance of particular markings or rings.
YOU WILL NEED: a tree cookie or a worksheet showing tree rings
Drawing a Twig
28. Draw a twig. We loved this YouTube video that leads you step-by-step in drawing a twig. It is easy to follow. Even my 5 year old drew the twig quite well. What I love about the video is that the artist talks about the different growths on the twig, and made us all notice parts of a tree that we would not have otherwise noticed. After drawing our twigs, we immediately went outside to locate the parts we had drawn on a real tree. We were all excited to be able to identify something we had never noticed before!
YOU WILL NEED: paper and pencils
Snack & Review
29. Serve the Tree Nut & Fruit Balls and pine needle tea (optional).
YOU WILL NEED: napkins & cup for water
30. Review what we learned about roots, stems, leaves, and trees.
Optional Homework #1: Tree Identifications and Tree Poem
Have children draw and identify at least 5 trees. We included leaf and bark rubbings of each tree. It is helpful to use one side of the sheet to do a leaf rubbing and the other side of the sheet to do the bark rubbing. We noticed that some crayon brands and colors worked better than others, so try to switch out any crayons that do not seem to be producing clear images.
Also have the children memorize the poem "Trees" by Joyce Kilmer.
Optional Homework #2: Create an Edible Leaf Structure
1. Sliced bananas will be the stomata, which are mainly found under the leaf, and green jell-o will be the lower epidermis. Cool the banana and green jell-o mix in a freezer for 30 minutes and continue on with the lesson. Mention the functions of the epidermis and stomata. We compared the stomata to our noses and mouth as it takes in and releases gas. (This came from Ranger Rick's Naturescope book Trees Are Terrific.)
YOU WILL NEED: 1 8x11" glass pan, a knife and cutting board, a small mixing bowl, a mixing spoon, 1 sliced banana, and 1 package of green jell-o
Veins & Spongy Layer
2. Discuss the importance of the veins and the spongy layer. Strawberry slivers or peach slivers will represent the vein, small cantaloupe or honeydew melon chunks will represent the loosely packed, irregularly shaped cells and the yellow or peach jell-o will represent the spongy layer. Place in the freezer for 30 minutes. (Note: The fruit slivers that represent the veins will float around in the jell-o mixture, so there is not a need to place them carefully in straight lines on the jell-o.)
YOU WILL NEED: a small bowl, a mixing spoon, 5 strawberries cut into slivers or 1/2 a peach cut into slivers, 8 small cantaloupe or honeydew melon chunks, & a box of peach or yellow jell-o
3. Discuss the importance of the palisade layer. Grape halves will represent the chloroplasts and the peach or yellow jell-o will represent the palisade layer. Freeze for 30 minutes.
YOU WILL NEED: 10 grapes, a knife, cutting board, a small mixing bowl, a mixing spoon, & a box of peach or yellow jell-o
4. Add the remaining 1 cup of green jell-o liquid to the top. The upper epidermis will be represented by the remaining green jell-o. Review the purpose of the epidermis. Freeze for 30 minutes.
5. Waxy Layer: Discuss the importance of the waxy layer. Cool Whip will represent the waxy layer. Slice up the Edible Leaf Structure and review the parts of a leaf and what each part does. Enjoy eating your leaf!
YOU WILL NEED: Cool Whip and mixing spoon
Optional Homework #3: Free Tree Lapbooks
Maple Syrup Unit & Lapbook : http://www.homeschoolshare.com/maple_syrup.php
Lapbook based on Meeting Trees by Scott Russell Sanders : http://www.homeschoolshare.com/meeting_trees.php
Lapbook based on The Giving Tree by Shel Silverstein : http://www.homeschoolshare.com/giving_tree.php
Lapbook based on The Lorax by Dr. Seuss : http://www.homeschoolshare.com/lorax.php
Lapbook based on Miss Twiggley's Tree by Dorothea Warren Fox : http://www.homeschoolshare.com/miss-twiggleys-tree.php
Lapbook based on The Tale of Three Trees by Angela Elwell Hunt : http://www.homeschoolshare.com/tale_of_the_three_trees.php
Our Favorite Books on Roots & Stems:
- What Do Roots Do? by Kathleen V. Kudlinski
- Plant Plumbing: A Book About Roots and Stems by Susan Blackaby
Our Favorite Books on Leaves:
- Why Do Leaves Change Color? (Let's-Read-and-Find-Out Science, Stage 2) by Betsy Maestro
- Leaves! Leaves! Leaves! by Nancy Elizabeth Wallace
- Leaf Man by Lois Ehlert is a cute picture book prefect for preschoolers or kindergarten aged children and might inspire a craft
- Investigating Why Leaves Change Their Color (Science Detectives) by Ellen Rene has photographs rather than illustrations but does a wonderful job of explaining why leaves change colors
Our Favorite Books on Photosynthesis:
- Understanding Photosynthesis with Max Axiom by Liam O'Donnell was our favorite book on plant systems, and photosynthesis in particular. It does a wonderful job of explaining the process in terms that even younger children can enjoy, and the information is told by a cool scientist who can shrink in order to investigate leaves more thoroughly. It is written in a comic book format, so the pictures will be too small to use as a read aloud for a larger group. If you are reading to a class that is larger (16+ children),
- The Magic School Bus Gets Planted: A Book About Photosynthesis by Lenore Notkin
- Living Sunlight: How Plants Bring The Earth To Life by Molly Bang
Our Favorite Books on Trees:
- I Can Name 50 Trees Today!: All About Trees (Cat in the Hat's Learning Library) by Bonnie Worth was our favorite picture book that goes over what aspects to look for when identifying trees. My children are especially fond of how it is written in a rhyming Cat in the Hat Dr. Seuss style.
- The Secret Life of Trees, Level 2: Beginning to Read Alone (DK Readers) by Chiara Chevallier
- The World's Largest Plants: A Book About Trees (Growing Things) by Susan Blackaby covers the basics about a tree including parts, conifers vs. broad-leaf, food making, stem, etc. - and it has just the right amount of text on each page to keep the attention of my preschooler while providing enough educational information for my 2nd grader.
- A Tree Is a Plant (Let's-Read-and-Find-Out Science) by Clyde Robert Bulla follows an apple tree as it grows from a seed to a full size tree and then through the various seasons.
- Nature All Around: Trees by Pamela Hickman
How botanists learned about photosynthesis
Go on a seed hunt, act out germination, create seed mosaics, make and eat a plant parts salad, dissect a flower, decorate sunflower cookies, compete in a photosynthesis relay race, got on a plant scavenger hunt, and more during this fun four part unit study on Botany and Plants!
- Plant Parts & Seeds Lesson - This is part 1 of a 4 part unit study on Botany and Plants. Go on a seed hunt, act out germination, create seed mosaics, make and eat a plant parts salad, and more in this fun lesson on plants!
- Flowers Lesson - Go on a flower hunt, dissect a flower, create edible flowers, paint flowers, and more in this fun lesson on flowers! This is part 2 of a 4 part unit study on Botany and Plants.
- Bee & Honey Lesson - This is part 3 of a 4 part unit study on Botany and Plants. (This lesson is optional if you need to squeeze this unit into 3 parts rather than 4.) Dance like a bee, make edible bees using honey balls, use cheese puff balls and and juice boxes to dramatize pollination, create pipe cleaner bees and have them fly to the tune of Flight of the Bumblebee, and more!