Watch and in time the food colouring will be sucked up the stem along tiny tubes (called vessels) and the petals of the flower will start to change in colour.Another way to try this experiment is to get a flower with a long, thick stem (or a celery stalk with leaves) and slit it carefully from the bottom and put one end in separate test tubes (with different food colourings). Your flower (or celery) should have petals (or leaves) in two different colours.Did you know that plants need water to live? As well as absorbing water from the atmosphere (air) through their leaves, they suck water up through their stems. If you used the celery stalk for the above experiment you could cut the stalk and see that the little holes inside are coloured.
Jar, Plastic Cup or Test Tube
A Flower (light coloured-white carnation) or Celery Stalk (with leaves)