Friday, May 2, 2008

Our Little Celery Experiment

We are working on a biology unit. Our current topic is plants and on Monday, April 28th (the day we studied stems) we started an experiment with celery and colored water. We put one stalk in red water, one in blue water, and we split one and put a part in each color. When asked what they thought would happen, the kids said, "The celery in the red water will turn red, the celery in the blue water will turn blue, and the celery in both will turn purple." I bit my tongue and let them wait to see what would happen for themselves.

This is what the celery looked like on Wednesday, April 30th. The split celery had one side with red coloring, the other side had blue coloring, and the stalk was bent. The stalk in the red water did have red coloring, but it didn't look very healthy. The stalk in the blue water had blue coloring and actually looked better than it did starting out.

It didn't take long (probably within an hour or two of starting the experiment) for the kids to realize that the split celery would not turn purple. They had several good ideas of how we could get purple celery though. Some wanted to switch the stalks to the opposite cups, some wanted to mix the blue and red water and start over with a new stalk, and some wanted to make new colored water with red and blue food coloring and use a new stalk.


weavermom said...

We're planning to do this in a couple of weeks. I didn't think about splitting the stalk! What a great idea to make it a little more interesting for my older one who has done this before. Thanks!

Brandi said...

You're welcome! Have fun!

Damama T said...

COOLNESS! Are you sure somebody didn't have a midnight snack and just put a new stalk in the blue? It sure looks like it more leaves than it started out with. LOL!

Does this experiment teach us that red dye is bad for living things and blue is good? Just might explain why RED cake icing tastes so nasty, too. LOL!

Brandi said...


No one snacked on the celery. There were some leaves that weren't open and when we put it in the water they opened. Some of the leaves on the stalk in red water opened as well, but not as well.

I myself have been wondering if the "evil" red dye was exposed in this experiment, or if the red interfered with the chlorophyll aiding in food production. Without doing a more extensive experiment we really can't draw any conclusions. Perhaps when we come back to this unit in later years, we can do a more extensive experiment. That will make it more interesting for the kids, who will of course all be older. Baby Bear will be 8 or 9 when we do this unit again and Froggie will be18 or 19. I'll have to make note of this in our curriculum.