I remember doing this as a child and being fascinated, and I love finding fun ways to introduce science to my toddler, so I was excited to do this experiment with her. We bought a small bouquet of white carnations and added food colouring to six glasses of water, making each glass a different colour of the rainbow.
How it works:
Flowers transport water through their stems (from the roots in the case of planted flowers). As water evaporates from the petals, buds, and leaves, more water is pulled up through the stem (known as transpiration). As water evaporates, more water is “pulled up” to fill the space in the tiny tubes inside the stem left by the evaporated water, this is movement process is called capillary action. Colouring the water makes it possible to track the movement of water into the flower, without harming the flower.
Our observations:
- Within an hour or so, the flowers had already begun to show colour in the some of the petals; the blue was the first to show
- The red showed the least, which I was surprised by – I imagined the yellow would show the least due it being the lightest colour
- The blue and purple both looked the same in the flower
*This can also be done using celery.
4kids2moms 