Grow Mint in Water: Easy Preschool Science Activity

Engage your young learners with a hands-on science project by growing mint from cuttings. This activity combines STEM and gardening, offering students a chance to experiment, observe, measure, plant growth. It’s a budget-friendly project that’s simple to set up and can result in potted mint plants for students to take home in a few weeks.

The Benefits of Growing Plants from Cuttings for Young Learners

Gardening activities teach children about the life cycle of plants, but they often miss out on what happens below the soil. Growing cuttings in water allows them to witness root and leaf development firsthand, making it easy for even young preschoolers to understand how plants develop..

Getting Started: Preparing Your Mint Cuttings

To begin, buy a large pot of live mint from the grocery store. With 15 students in my class, I aim for a pot with 20-25 stems. Children will handle their mint plants frequently, and some cuttings may not survive. It’s a good idea to have extra cuttings ready to replace any that don’t make it.

Materials Needed for Mint Cuttings

• Scissors
• Rubbing Alcohol and cotton ball
• Mint plants
• Small jars
• Water
• Magnifying Glasses
• Observation Pages (Use your own or Click here to Purchase)

Lesson Preparation

Before starting this experiment, take a few minutes to prepare your jars and scissors.

1. Disinfect the scissors by wiping the blades with a cotton ball soaked in rubbing alcohol.

2. Label individual jars with each child’s name.

Lesson Introduction

1. Begin by showing the class a mint plant and identifying the stem, leaves, and roots. Next, ask the students how they think plants grow. Show them mint seeds or pictures of mint seeds if available.
2. Explain that while many plants grow from seeds, some can grow from cuttings, a process called propagation. The piece you cut is known as a cutting.
3. Finally, pass around a few mint leaves for the students to feel and smell, asking if they recognize the scent.

Demonstration: How to Take a Mint Cutting

Demonstrate how to prepare a mint cutting for propagation. First, carefully snip a 4-6 inch piece of mint stem just below a set of leaves. Next, show the children how to pinch off the lower leaves, keeping only 2-4 leaves at the top of the stem. After that, point out that the spots on the stem where you removed the leaves are called nodes, and the roots will grow from these places. Finally, pass around the cutting so the children can see it up close.

Possible questions to ask your students:

• Do you think the mint will grow in water?
• Which do you think will grow first: leaves, stems, or roots?
• How many days do you think it will take for the leaves, stems, or roots to grow?

Step-by-Step Instructions

1. Fill the jars with water.
2. Have each child cut a piece of mint as demonstrated. Pinch off all leaves except the top set. If the stems are too long, children can trim them, ensuring at least one leaf node is left for roots to grow.
3. Provide magnifying glasses so students can make observations.
4. Place each stem in a labeled jar of water, ensuring the top leaves are not submerged.
5. Position the cutting and jar in a window that receives indirect light.
6. Allow students to taste the leaves they removed, if desired.
7. Change the water every 2-3 days.
8. For at least the next week, continue to observe the mint cuttings.

Note: After all the stems of the mint are trimmed down, water the pot and place the container in the window. This mint plant should start regrowing within days.

Observing the Mint Cuttings

• In 3-5 days, small roots should start to appear. First, use magnifying glasses to let the students examine the roots. Than, have students record what they see on an observation page. You can make your own, or purchase a set here.
• Encourage students to compare their mint cuttings with their classmates’. Look for variations in root and leaf growth. If you still have the original potted mint, gently pull one plant out to compare its roots with the cuttings in water.
• Finally, as the roots and leaves continue to grow, transfer the cuttings to small pots once they have developed a solid root system. Students can then take their new mint plants home.

Note: Mint spreads by sending out rhizomes, which allows it to cover a larger area quickly. It can easily take over a garden bed. The easiest way to keep it under control is to grow it in a container either outside or in a sunny window.

Connecting the Project to the Scientific Method

Growing mint from cuttings is an excellent way to introduce preschoolers to the scientific method. Here’s a simplified process:

1. Ask a Question: Can we grow a new mint plant from a cutting?
2. Make a Hypothesis: If we put a mint cutting in water, then it will grow roots.
3. Conduct an Experiment: Place cuttings in water.
4. Record Data: Observe and document changes using magnifying glasses and observation sheets.
5. Share Findings: Compare results with classmates and plant the cuttings to take home.

Extending the Learning: Experiment with Other Herbs

Try this propagation project with other herbs like basil, thyme, or oregano. Basil roots within days, thyme root within a couple of weeks, and oregano may take up to a month.

Read more about regrowing basil here.

This mint propagation activity is a wonderful way for children to learn about plant growth and care. If you give this project a try with mint or any other suggested herb, I’d love to hear about your experiences!

Make planning easy by picking up this bundle of plant science experiments from my TPT store. This set has lesson plans and observations for water propagating mint, green onions, and basil.

My Favorite Resources

Note: I don’t earn any commission from these links, I just want to share items that have worked well for me!

Magnifying Glasses: Toddler or 3’s

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