Celery can show how water moves inside plants in a way you can see with your own eyes. When celery stalks sit in cups of colored water, the color travels upward into the leaves. After 24 to 48 hours, the leaf edges and veins may turn blue, red, or green.
This project matters because it helps students understand how plants drink water from their roots to their leaves.
Key Facts
- Capillary action helps water move upward through tiny tubes in plants.
- Xylem tubes carry water from the bottom of the celery stalk to the leaves.
- Colored water makes the path of water easier to see.
- Most celery color changes are easiest to see after 24 to 48 hours.
- Distance traveled = final height - starting height.
- Average speed = distance traveled / time.
Vocabulary
- Capillary action
- Capillary action is the movement of water through tiny spaces, even upward against gravity.
- Xylem
- Xylem is the plant tissue made of tiny tubes that carry water upward.
- Stalk
- A stalk is the long, firm stem part of the celery that supports the leaves.
- Food coloring
- Food coloring is a safe dye used to add bright color to water in this experiment.
- Observation
- An observation is something you notice and record using your senses or tools.
Common Mistakes to Avoid
- Using celery without leaves, because the color change is much easier to see in leafy tops and leaf veins.
- Adding only a tiny drop of food coloring, because weak color may be too pale to show the water path clearly.
- Checking for results after only a few minutes, because the color usually needs many hours to move through the celery.
- Forgetting to cut the bottom of the stalk, because a fresh cut helps the celery take up water more easily.
Practice Questions
- 1 A celery stalk is placed in blue water at 9:00 a.m. By 9:00 a.m. the next day, the blue color has moved 12 cm up the stalk. What was the average speed in cm per hour?
- 2 Three cups each have 100 mL of water. You add 5 drops of blue food coloring to one cup, 5 drops of red to another, and 5 drops of green to the third. How many drops of food coloring did you use in all?
- 3 A student sees red lines inside a celery cross-section after the celery sat in red water overnight. Explain what those red lines show about how water moves in the plant.