Activity: 10 mins, setup; 12+ hours, experiment run time
Recommended Grades: Pre-K - 5
Objective: Observe capillary action, which is the ability of liquids to travel up through narrow spaces without the application of additional forces. This process helps plants move water from their roots up through the rest of the plant.

• Celery stalks (preferably with the leaves)
• Glass jars
• Water
• Food coloring

1. Start with a clear glass jar. To try multiple colors, have a jar for each color.
2. Fill the jar halfway with water.
3. Add drops of food coloring until you get your desired color.
4. Put celery in a jar. For better results, make sure the stalk has leaves at the top.
5. Leave the jar overnight and observe what has happened to the celery. Cut the bottom of the celery stalk and examine what you see.

Plants have the ability to absorb water from the roots so that every part of the plant gets the nutrients and water it needs. This is called “capillary action.” Once the water reaches the leaves, it evaporates. The plant’s stomata—tiny pores of tree leaves or needles—open up. Water enters the atmosphere as water vapor through the stomata, a process called “transpiration.” The stomata are also the structures that let carbon dioxide into the plant to help it create its food.

Option: Try the same experiment using a white flower in place of the celery.