demonstrations:celery_capillary_action
Celery Capillary Action
Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Fluids and Surface Tension, Plants
Alternative titles: Color Changing Celery
Summary
Celery is placed in colored water and the colors move upwards to it's leaves.
Procedure
- Gather a celery stalk with leaves, 2 tall clear glasses, water, red and blue food colouring, and a sharp kitchen knife.
- Cut a thin slice off the base of the celery to freshly open the xylem tubes.
- Make a vertical slit about 5 cm up the middle of the stalk so the base splits into two prongs.
- Fill two glasses halfway with cold water; tint one glass red and the other blue with food coloring.
- Place one prong of the split base into the red glass and the other prong into the blue glass. Ensure the leaves remain above the rims.
- Leave undisturbed and observe colour changes in veins and leaves after 30 minutes; for full effect, check again after several hours or overnight.
- Examine the stalk closely. Then cut cross sections near the base and mid stalk to see dyed xylem rings and channels.
Links
Celery Capillary Action - Wild Random Videos:
The Color-Changing Celery Experiment! - SciShow Kids:
📄 Capillary Action - Science World: https://www.scienceworld.ca/resource/capillary-action/
📄 An Experiment In Capillary Action – Celery Science - Emmymade: https://www.emmymade.com/an-experiment-in-capillary-action-celery-science/
Variations
- Try white flowers such as carnations with split stems to feed two colours and create bicolour petals.
Safety Precautions
Safety Precautions
- Use a sharp knife only with adult supervision; cut on a stable board with fingers clear of the blade.
- Food coloring can stain skin and surfaces; protect the work area and clean spills promptly.
- Do not eat plant material used as teaching specimens, especially if handled in a lab setting.
- Wash hands after handling plant material and dyes.
Questions to Consider
- How do plants get water from underground into stems and leaves? (Through xylem using capillary action and transpiration pull.)
- Why do colors appear in specific veins first? (Xylem bundles are discrete tubes that channel water along set paths.)
- What roles do cohesion and adhesion play in this activity? (Cohesion holds water molecules together; adhesion helps them climb tube walls.)
- Why does a fresh cut at the base matter? (It opens clogged or crushed xylem, improving flow.)