Valentine's Day schooling

Today we wanted to have a little fun since it's a holiday that public schools have always made a big deal of. It's the kids first year of homeschooling and I'm too pregnant to try to attend functions with the local homeschool groups. We decided (since we are studying plants and their vascular systems) to watch carnations "drink".
We just took white carnations and cut the stems at an angle and placed them in water with about 20 drops if food coloring. We split one stem to get a half and half effect.
They turned out beautifully! We started noticing the colors change within an hour but around dinner time they were very vibrant already. We noticed the blue worked the best.