Raise a rainbow

Demonstrate in living color the amazing way that plants drink.

You'll Need

  • Food coloring
  • Celery
  • Cups

Time

30 minutes

By Candace Lindemann
Children's Author & Education Consultant

Candace Lindemann is a published children’s writer and educational consultant. She holds a B.A. from Yale University and an M.Ed. from the Harvard Graduate School of Education. You can also find Candace blogging at http://NaturallyEducational.com. While Candace’s degrees prepared her for a career in education, she’s found that the best preparation for parenting is on-the-job training.

Plants need water. They "drink" the water through the tubes (like straws) in their stems. This dye activity gives a visual of how this process takes place.  

This also opens up an opportunity to introduce the scientific method and start a "science journal," in which children can record their observations. Toddlers can color in diagrams and even glue on printed labels with help.

Directions:

  1. Mix 4-6 drops of food coloring in a half cup of water. Use a separate cup for each color.
  2. Trim the bottom of the celery stalks and place in the cup. Ask your child to hypothesize (guess) what will happen.
  3. Observe the plants at 30 minutes, 1 hour, 3 hours, and overnight, if possible. Record your observations. (For the youngest kids, you can give them drawings of the plant and allow them to color them in.)
  4. Cut a cross-section at the base of the stalk or stem and record your observations.

Older kids might be interested to know that these tubes are vascular bundles that contain xylem and phloem. These vascular bundles function like our own circulatory system of veins, bringing water and some nutrients from the roots to the leaves (xylem) and food from the leaves to the rest of the plant (phloem).

Try these variations next:

  • Split the bottom of the stalk and put each half in a different color. Does the plant end up a blend of the colors (red + blue = purple) or half one color, half the other?
  • Instead of celery, try white carnations.