I can transport water!

Just like humans, plants need water to survive. But how can plants "drink" water?
The process by which plants absorb water (and nutrients dissolved in it) from the soil via the roots is called osmosis. When transported against gravity from bottom to top, the evaporation of water on the leaves in the upper part of the plant acts like a suction. This pulls the water out of the soil through the plant upwards. With the help of these forces, trees can grow up to 130 metres high, for example.

You can make the water absorption of the plant visible by using coloured water.


    Experimental setting



    • Fill 3 glasses with water
    • To one glass add red coloring and blue coloring in another one
    • Place a flower in each glass




    After 5 days
    • The red and blue colored water has been transported from the lower part of the plant to the flower and is visible in the veins of the flower petals.

    You need

    • 3 glasses
    • Water
    • 3 plants with white flowers (roses work very well!)
    • Red and blue foord coloring
    Heinrich Heine University
    University of Cologne
    Max Planck Institute for Plant Breeding Research
    Forschungszentrum Jülich