Color Changing Flowers

Watching a white flower change color feels like magic—but it’s actually science in action!

In this easy color changing flower experiment, kids explore how water moves through plants using a simple setup with food coloring. This hands-on activity is perfect for learning about capillary action, plant structure, and how flowers get the water they need to survive.

This experiment works well at home or in the classroom and can easily be turned into a full flower science project for kids.

👉 Looking for a full week of activities? Try this 7-day spring flower lesson plan for kids with science, art, and observation.

Flower Science Experiment

Field: Life Science—Plant Biology
Grades: K–4
Concepts Explored: Capillary action, water transport in plants, plant structure, observation skills

Supplies Needed

• White flowers (carnations work best)
• Clear cups or jars
• Water
• Food coloring (variety of colors)
• Scissors
• Optional: paper towels for easy cleanup

How-To Instructions

1. Fill each cup with water about halfway.
2. Add several drops of food coloring to each cup and mix well.
3. Trim the stems of your flowers at an angle (adult help recommended).
4. Place one flower into each cup of colored water.
5. Observe over time—check back after a few hours and again the next day.

👉 Optional: Split the stem in half and place each side in a different color for a two-tone flower!

Color Changing Flower Science Information

Plants need water to survive, but they don’t have a pump like animals do. Instead, they rely on a process called capillary action to move water through their stems.

Capillary action happens when water travels through tiny tubes inside the plant called xylem.

Here’s how it works:

• Water sticks to the walls of the tubes (adhesion)
• Water molecules stick to each other (cohesion)
• This creates a pulling force that moves water upward

As the colored water travels up the stem, it reaches the petals, carrying the dye along. That’s what causes the flower to change color!

This is the same way real plants move water from their roots to their leaves and flowers every day.

💡 Tip: The fresher the flower, the better the results because water can move more easily through the stem.

👉 You can learn more about capillary action here

More Facts for Kids

• Plants are made up of tiny tubes that carry water and nutrients
• Flowers need water to stay firm and upright
• Without water, plants wilt and droop
• White flowers work best because they show color clearly
• This process happens naturally in all plants—even without food coloring

Make It a Flower Science Project

Turn this activity into a full color changing flowers science project by testing different variables:

Try changing one thing at a time:

• Use different types of flowers
• Change the amount of food coloring
• Compare warm vs cold water
• Place flowers in light vs shade

Ask questions like:

• Which flower changed color the fastest?
• Does more dye make a bigger difference?
• How long does it take for the color to reach the petals?

👉 Learn more about using the scientific method for kids here. Record observations and compare results.

Extension Activities

• Try a flower dissection activity to explore plant parts
• Create a scientific illustration journal page of your flower before and after
• Pair with a flower labeling worksheet
• Explore how plants drink water with other simple plant experiments

👉 For a full week of connected activities, try this spring flower lesson plan for kids

Related Science Activities

• Spring science activities for kids
• Plant science activities for kids
• Life science activities for kids
• Flower crafts and STEAM Projects for kids

Color Changing Flower FAQ

Why do flowers change color in this experiment?
The colored water travels through the stem and into the petals through capillary action.

How long does it take to see results?
You may see changes within a few hours, but full results usually take about 24 hours.

What flowers work best?
White carnations, daisies, and roses work best because they absorb color clearly.