Try a Mint Water Roots Experiment This Summer
If you’ve been learning about plants this summer and are looking for a simple science activity to try at home, why not experiment with growing mint in water?
Many plant experiments involve giving different plants varying amounts of light, water, or nutrients and comparing the results. While those can be interesting, they often involve intentionally depriving one plant of something it needs. This experiment is a little different. Instead, children can observe how a plant grows new roots and begins creating an entirely new plant from a cutting.
And it is an experiment that gives us a unique perspective on root formation. Watch them grow right before your eyes in the water!
All you need is a fresh sprig of mint and a small container of water. Remove the lower leaves so that only the stem sits below the waterline, then place it somewhere bright but out of direct sunlight.
Over the following days and weeks, watch carefully. Can you spot the first roots appearing? How quickly do they grow? What changes happen to the leaves and stem?
Encourage children to make predictions, measure root growth, sketch their observations, or take photographs to create a plant diary. It’s a great way to learn about plant reproduction, root systems, observation skills, and the conditions plants need to thrive.
Below are photographs from our own mint water roots experiment. Ours has now been around two weeks since we started. We were amazed by how quickly the roots appeared and how much growth happened in just a short period of time.
Have you tried growing plants from cuttings? We’d love to hear about your experiments!
What You’ll Need
This is a wonderfully low-cost experiment, and you may already have everything you need at home.
For our experiment, we used:
- A healthy mint cutting
- An old gherkin jar (any clean glass jar will do)
- Ordinary tap water
- A bright windowsill
Conditions
Mint is very hardy and forgiving, which makes it an excellent plant for beginner gardeners and young scientists.
Light: Bright, indirect light is ideal. A sunny windowsill works well, but avoid placing the jar in intense direct sunlight all day, as this can encourage algae growth and overheat the water. We put ours in front of a frosted window.
Temperature: Normal household temperatures are perfect. Around 15–25°C is ideal, so no special equipment is needed.
Water: We simply used ordinary tap water. Fill the jar so that the lower part of the stem sits in the water, but keep the leaves above the waterline. If the water becomes cloudy, replace it with fresh water.
Time: Be patient! Some cuttings begin producing roots within a few days, while others can take a couple of weeks. Observing the changes is all part of the experiment. Maybe do two jars and see which sprouts first!
One of the things we loved about this activity was how simple it was. There was no need for special plant food, expensive equipment, or even a garden. Just a mint cutting, a jar, some water, and a little bit of curiosity.
