I have set up this experiment for Science week again this year. This time I used the celery stalks in the centre of the celery which are newer and paler, so thirstier! The results were a lot more dramatic and we could see the colour in the leaves within hours.
I forgot to take a photo of the bottom of the stalk but when the experiment is finished cut off the bottom and you can clearly see the little dots which are the ends of the tubes. They are brightly coloured by the dye as it travels up the tube inside the stalk.
It’s a good chance to talk about how water and nutrients travel through our own bodies.
Plants absorb water by osmosis (gradual absorption). The water travels up tubes in the stems to all parts of the plants. The plants use the water in a process called photosynthesis to make food.
We have added food coloring to the water so that we can see where the water has been absorbed by the plant.