Looking for inexpensive and interactive STEM activities for your classroom? Conducting science experiments with plants is an easy way to incorporate hands-on experiences to your curriculum.
Working with seeds and leaves can teach your students about much more than capillary action, germination, and photosynthesis. It can provide valuable lessons in caring for living things, collecting data, and using the scientific method.
The following hands-on plant science activities are easy to integrate into your kindergarten, elementary, or middle school classroom. Although we’ve grouped them according to age, some work well with children of all ages and several can be easily adapted for different age groups and abilities.
Some can be done in the course of a single afternoon, others may lead to long-term observations of a plant’s progress or even a class garden that can be transferred outside in the spring.
Science Seedlings for K-2 Learners
Teaching children about how plants work is often a simple a matter of building on their natural curiosity. Your kindergarten and elementary students may have questions about how plants “eat,” “drink,” or grow.
Here are a few simple experiments to start with:
How leaves get water
What leaves need to germinate
How water travels through plants
How leaves breathe
If fresh pine cones are readily available in your area, you might also discuss what pine cones are for, and show your students why they open and close.
K-2 students are also ready to grow and germinate seedlings – beans happen to be easy to germinate and very inexpensive to work with. With some natural light and a wet paper towel, you can germinate seeds in plastic bags so that students can see the gradual changes in the seeds as they opens up.
Some simple experiments with seeds in small plastic cups or egg cartons can also teach students exactly what seeds need in order to grow.
Even at this age, your students can record brief observations such as whether they watered a plant and how tall it has become. Filling in a simple chart like this one to monitor plant growth lets nascent readers and writers practice their literacy skills while being scientists.
Herbs like basil, mint, and thyme work well in classrooms because they grow quickly, as does aloe vera, which requires hardly any maintenance.
Going Beyond Germination in Grades 3–5
Older students can not only handle the responsibility of caring for plants in the classroom, they can also work with more challenging varieties of plants. They can even begin designing experiments by choosing subjects and isolating variables.
For example, they might try sprouting the same species in different types of soils, or do the opposite, and test out a variety of seeds in the soil native to your area.
Growing “spuds in tubs” or “cabbage clones” in the classroom gives your students a taste of traditional agriculture – and they may actually be able to eat what they produce!
Working with plant clones is also an easy way to introduce the notion that different living things reproduce in different ways – a biological fundamental that may very well amaze your students. You could also connect these activities to lessons in history and geography: a unit about Eastern Europe or Ireland, for example.
The way leaves change color in the fall is fascinating no matter how old you are, and discovering the different pigments which make that change possible is a great way for students to begin learning about photosynthesis.
Try out this activity near the start of the school year, when the leaves in your area are likely still green. Then, when the leaves start changing in the fall, make sure to reflect back on the experiment and see if your class could predict what colors their local trees would become.
Branching Out in the Middle Years
Starting in sixth grade, students are ready to truly start experimenting with plants. They can begin using the scientific method to perform and design plant science experiments, and begin exploring the many places where plant science intersects with engineering, chemistry, physics.
Understanding photosynthesis is a key launching point for plant science explorations in high school and beyond. However, all too often photosynthesis is taught as a complex chemical equation, which can be difficult for students to remember or comprehend.
This low-tech experiment with leaf disks has become a classic because it enables students to see and document photosynthesis while it’s happening. It also helps them remember the elements necessary for photosynthesis to occur: light, water, and carbon.
The idea that plants need light is something younger schoolchildren can easily grasp. Older students can develop and deepen that knowledge by experimenting with phototropism: plants’ tendency to grow towards their light source.
Students could conduct experiments to see what color of light different plant species prefer. You could also challenge your them to design and build shoebox mazes for plants to navigate while growing towards the light.
With these experiments, you can either give your students a clear goal and directions to follow, or you can encourage your students to create their own hypotheses and design experiments to test them.
As your students gain more knowledge of biology and ecology, you can incorporate plant science experiments into larger units about the environment. For example, here is a simple experiment in which students test how man-made chemicals affect the growth of algae. Like terrestrial plans, algae depends on photosynthesis, but it also grows relatively quickly, so you’ll be able to see results within only one or two weeks.
This water filtration experiment demonstrates how essential plants are for the welfare of our soil and water. To get started, create three miniature milk-carton landscapes: one with living plants, one with dead leaves and sticks, and one with no plant matter at all. Then, pour water into each of them and harvest whatever “groundwater” drips out. The landscape with plants should have the clearest groundwater of all.
To take this experiment to a higher level, have your students perform a couple of chemical tests on your groundwater using paper test strips. You may be surprised to discover what chemicals the soil contains!
Creating Strong Scientific Roots
Classroom plant science is about much more than basic agriculture. It’s an essential step for children in learning how science works and in becoming good environmental stewards. It can be incredibly rewarding for your students and, through hands-on experience, give them lessons in problem solving, patience, diligence and teamwork that will last a lifetime.
Check out more plant science links over on our Pinterest board, and tell us about your plant science experiments, too. What plant science hypotheses have your students tested? What have you grown in your classroom?