you will need:
3 sticks of celery, leaves still attached (you can add this to your Riverford order if it isn’t already in your box)
food colouring – you could try red, orange and green
1. Break off 3 sticks of celery, keeping the leaves on.
2. Put each stick in a glass of water, adding a different colour to each glass. You’ll only need a few drops.
3. Watch and see what happens over the next few days. When you slice through the stem you’ll see the xylem coloured with the food colouring.