Coloring Carnations Science Experiment

Using food coloring in a water bottle to change the color of carnations

Florist making a bouquet of flowers
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This fun home or school experiment shows your child how water flows through a flower from stem to petals, changing the color of carnations. If you've ever had cut flowers in a vase around the house, your child might have observed the water levels dropping. Your child may wonder why you have to keep watering houseplants. Where does all that water go?

The Coloring Carnations Science Experiment helps to demonstrate that the water isn't just vanishing into thin air. Plus, in the end, you'll have a very pretty bouquet of flowers.

Materials You Will Need

  • White carnations (1 for each color you would like to try to create)
  • empty water bottles (1 for each carnation)
  • food coloring
  • water
  • 24 to 48 hours
  • Coloring Carnations Recording Sheet

Directions for Coloring Carnations Experiment

  1. Peel the labels off the water bottles and fill each bottle about one-third full of water.
  2. Have your child add food coloring to each bottle, about 10 to 20 drops to make the color vibrant. If you would like to try to make a rainbow bouquet of carnations, you and your child will need to mix the primary colors to make purple and orange. (Most boxes of food coloring include a bottle of green.)
  3. Cut the stem of each carnation at an angle and place one in each water bottle. If your child wants to keep a picture diary of what is happening to the carnations, download and print the Coloring Carnations Recording Sheet and draw the first picture.
  4. Check the carnations every few hours to see if anything is happening. Some of the brighter colors may begin to show results in as little as two or three hours. Once you begin to see visible results, it's a good time to have your child draw the second picture. Just remember to record how many hours have gone by!
  5. Keep an eye on the flowers for a day. By the end of day one, the flowers should really be taking on color. It's a good time to ask your child questions about what she's observing. Try questions along the line of:
    1. Which color is working the quickest?
    2. What color isn't showing up well?
    3. Why do you think the carnations are turning colors? (see explanation below)
    4. Where is the color showing up?
    5. What do you think that means about which parts of the flower get the most food?
  6. At the end of the experiment (either one or two days, it depends on how vibrant you want your flowers to be) gather the carnations into one bouquet. It will look like a rainbow!

Recording Sheet for the Coloring Carnations Science Experiment

Make a four-box grid for your child to draw pictures of what happened in the experiment.

What we did first:

After ___ hours:

After 1 day:

What my flowers looked like:

Coloring Carnations Science Experiment

Why the Carnations Change Color

Like any other plant, carnations get their nutrients through the water they absorb from the dirt they are planted in. When the flowers are cut, they no longer have roots but continue to absorb water through their stems. As water evaporates from the leaves and petals of the plant, it "sticks" to other water molecules and pulls that water into the space left behind.

The water in the vase travels up the stem of the flower like a drinking straw and is distributed to all of the parts of the plant that now need water. Since the "nutrients" in the water are dyed, the dye also travels up the stem of the flower.

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Your Citation
Morin, Amanda. "Coloring Carnations Science Experiment." ThoughtCo, Aug. 26, 2020, Morin, Amanda. (2020, August 26). Coloring Carnations Science Experiment. Retrieved from Morin, Amanda. "Coloring Carnations Science Experiment." ThoughtCo. (accessed May 29, 2023).