Celebrate spring in style with this fun flower activity.
You will need
3 white flowers
3 vases (big bottles, jugs or similar)
blue food colouring
red food colouring
water
secateurs or large sharp scissors
What to do
Place some water into each of the three vases.
Add 20 drops of red food colouring to one vase, then add 20 drops of blue food colouring to a different vase. Leave the third vase without any colour. The third vase is your ‘control' for the experiment.
Cut one centimetre from the bottom of each flower stem using secateurs. Younger readers should have an adult help with this step and be careful with the secateurs.
Place one flower in each vase. Make sure the stem can reach the water or the flower will die.
Leave the flowers to soak up the water. Observe what happens to the flower and its leaves throughout the week.
We used lilies, but you could try other flowers. You could even try to make your own blue rose!
And if you're still curious, here are some other experiments you could try:
Type of flower – do all white flowers take up food colouring? Will some types of flowers take up more colour than others?
Time – track the intensity of colour over time. If you're feeling adventurous, pick up some paint swatches from the hardware store and compare the colour intensity to those.
Temperature – how does leaving the flower at room temperature or putting the flower in the fridge affect the uptake of colour?
Amount of food colouring – how does the amount of food colouring you add to the water affect the final colour of the flower?
Other colours – what other colours can you use? Can you use combinations of different food colouring to make new colours?
What's happening?
Water evaporates from the outer parts of plants including the flowers and leaves. As the water evaporates it draws more water up through the plant in little tubes called xylem. This process is called transpiration.
Transpiration is very important for distributing water through plants to keep them alive. Water travelling through the xylem also carries mineral nutrients for the plant and, in this activity, food dye.
The lines you see in the flowers and their leaves are the xylem highlighted by the dyes they have taken up.
