Learn how plants eat

Celery is green, we already know that. But we can alter its color thanks to a property of liquids known as capillarity. Find out how it is possible.

Are you ready to change the look of a stalk of celery? To perform the experiment, you will need the following materials:

✔ 4 cups (preferably plastic)
✔ food coloring
✔ Water
✔ 4 fresh celery stalks with leaves (preferably the lighter ones)


First, fill each glass halfway with water and add 10 drops of food coloring to each glass. Then, on a cutting board, lay the 4 celery stalks in a row so the leafy parts match up.

⛔ Ask an adult to cut off the ends of the celery so that the stalks are 6 inches (15 centimeters) long. Finally, put a stem in each glass without forgetting to write down the time you finished the procedure. After 24 hours, observe the coloration of the leaves and stem and have an adult make a cross section of each stem and record your observations.


We know that plants need water and nutrients to live and that most plants grow on land. But what is the process by which plants obtain the water and nutrients they need? Also, do the water and nutrients move to a specific place in the stem, or do they go to all parts of the stem? This experiment will help us answer all these questions.

Just as veins carry blood throughout our bodies, plants have veins that carry water. Plants filter water and minerals from the soil and absorb them through their roots through a process called capillarity.

The water and minerals (known as crude sap) are transported by small tubes called xylem throughout the plant and will be used during photosynthesis to produce the food necessary for the subsistence of the plant.

When we add food coloring to water, it travels with the water up the celery stems and into the leaves. The food coloring illustrates how plants receive their nutrients.

Variations on this experiment: You can use other plants for this experiment. For example, white carnations or cabbage leaves.

To observe the effect of different environmental factors, place one stalk of celery in the sun and another stalk of celery in the shade. You can also cut the celery at different time intervals. For example, every hour or every two hours and measure the distance the dye has traveled up the stem.