You will need:
- Pale/white flowers. Carnations work well.
- Vases / glass jars (number depends on how many different colours you want)
- Food dye (colours are personal choice)
- Water
Method:
- Put some water in the vases/jars.
- Add the food dye of your choice, enough so the water is a bold colour.
- Cut the stems of the flowers, enough so they fit in the jars comfortably (an adult may want to do this) and remove any leaves that would be submerged in the water.
- Put the flowers in the water, you can separate them into different jars to get a range of colours or just stick with one colour!
- Watch the flowers change colour over the next few hours – the longer you leave them in the stronger the colour will be.
- When you are happy with the colour, remove the flowers from the coloured water and replace with clean water, then put the flowers back in the clean water.
The Science Bit:
- Just like drinking through a straw, the flowers are ‘drinking’ the water through the stem, this is called transpiration.
- What we can see when we add colour to the water is just what normally happens when you put flowers in water, the water moves up the stem and through the flower. Because the petals are white the food dye does exactly what it says, it dyes the petals, and this won’t disappear when you put the flowers back in clean water.
Optional extras to try:
- What happens if you use warm water instead of cold water? Does it work better/quicker?
- What happens if you put the flowers from one food dye into another? Will blue and red make purple??
