Coloring celery

This is a fun, very kid-friendly science experiment that we've done before (you can our previous one here). It's the watch-how-plants-"drink"-water experiment. All you need is a vase, water, food coloring, and either celery, or a couple of carnations.

Since we had done this experiment before and Oliver remembered what was going to happen (the tips of the celery leaves would turn the color of the food coloring), we decided to take it a further step and add another color after the first day. 

We started out with red. After only 2 hours, we could already see the tips of the leaves changing color!

This was about 10 hours later:

And this is what we had 24 hours later:

Then we added blue! After about 8 hours, this is what we had:

And 24 hours later, this was the final result. It was really cool!