We learned about trees recently for Tree Day. We wanted to find out how trees and other plants absorb water. We put some food colouring into containers of water. Then we put some stalks of celery into the containers of water. After a few days, we noticed that the celery was starting to change colour. We were able to see how the water travelled up through the celery stalks, just like it does through the roots and stems of trees and other plants.