For our experiment we used glasses, water, celery and food colouring. Our control was a piece of celery placed into a glass of water without any additive. This control makes sure our experiment is working properly.
We filled the glasses with an equal amount of water and marked the water level with a marker. This will show us how much water the plant drinks. We added green food colouring to one glass and red food colouring to another glass. Nothing was added to the control.
We split the stalk of celery in two and put one half into the green food colouring and the other half into the red food colouring.
The next day we came back and observed our experiment. We could see that the water level in all glasses had decreased. The control had not changed but the other piece of celery had started to show signs of discolouration.