An Outdoor Transpiration Activity For Middle School
- Evans Kofi Amoah
- Jul 18
- 3 min read
Updated: Jul 19
One of my favorite things to do as a science teacher is to take my students for an outdoor activity. After weeks of classroom learning, our unit on transport in plants

presents the perfect excuse to go outside and study in nature. In this blog post, I’ll share with you a simple outdoor transpiration activity that is sure to excite and inspire your students.
Lead In:
I begin the class with a driving question: “ How much water can plants produce in 20 minutes?” Next, I lead a class discussion on how we can accurately collect and measure the water transpired by some species of plants on our school campus. Then I put students into groups of four and provide them with a whiteboard marker and mini whiteboards. I instruct them to brainstorm ideas on the materials and methods that can be used to collect water from leaves. I also ask them to illustrate how they will collect data on the mass of water produced by a plant at 0 minute, 10minutes, and 20 minutes.
At this stage, I welcome every idea students come up with and provide quick feedback if necessary. My goal here is to see if students can think critically and scientifically. Once I have visited each group and listened carefully to their ideas, I tell the class that although their ideas are great, we will follow the method I have prepared due to the lack of time and materials. I then demonstrate and explain the exact procedure that we will use, as listed below.
Material List per group:
A plastic bag
A piece of string
A timer
A digital scale ( can be shared by each group)
Going Outdoors :
Before the activity, assign or instruct each group to choose one plant they want to investigate. Then follow these steps:
Step 1: Measure and record the mass of the empty plastic bag.
Step 2: Grab at least 4 leaves and fit them into a plastic bag.
Step 3: Tie the open end of the plastic bag with a string.
Step 4: Set the timer for 10 minutes and wait.
Step 5: Carefully remove the plastic bag and measure the new mass on a scale.
Note: As best as you can, remove any insect or debris from the bag before you measure the mass. Also, remove the air by gently flattening the plastic bag.
Step 6: Repeat step #4 and set the timer for another 10 minutes.
Step 7: Measure and record the new mass of the plastic bag at 20 minutes.
Closing:
Once the investigation is over, we head back to the classroom. I ask each group to share their results with the class. Afterwards, students use the data to draw a bar graph to represent the amount of water transpired by the plant they investigated. I lead a brief discussion on potential errors from our experiments. We then conclude the activity and end the lesson.
Download the FREE activity sheet here:
By starting my transport unit with this engaging outdoor activity, my students gain real-world insights on the topic. I see genuine interest and curiosity in their eye from the endless questions they ask during and after the activity. This unique learning experience prepares them for deeper concepts on the phloem, xylem, and vascular bundles within vascular plants. Because they have experienced it, learning about it becomes easier.
So there you have it. A great way to introduce your next unit on transport in plants that is simple, requires little prep time, and is meaningful for your students. I hope you give it a try and come back to let me know how it went. Have a fantastic class!
If you are interested in other plant-related resources, check these out.
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