Wednesday, 16 April 2014

Nature - How do plants take in water?

Plants need water and sunlight to make food and grow. Its called photosynthesis. Ok, you know the drill. Lets show it to the tiny ones, how plants take in water!

All kids notice that plants need water. Many among us have plants at home that we take care of by watering daily and by exposing them to sufficient sunlight. So this experiment should not be a surprise to your little one. Though they do know that water is required by plants to grow, the experiment actually shows them how.

Most experiments that I saw online were with carnations - the beautiful flowers. The effect that coloured water has on the pristine white petals is breathtaking. But I found this site where the experiment was done with celery sticks. And I loved it for the reason that you will shortly know. So, either you can pick carnations or celery - thats your choice. The only other stuff that you will require are food colouring and different glasses of water for each colour that you use.

I took 3 colours - green, red and orange. The red and orange ended up looking quite similar, but those were the only 3 colours I had back then. I wasn't really sure if water colours would work, though now I do feel they might - maybe the next time we repeat this experiment, I'll try with water colours.

Fill up tall glasses with the coloured water till about half the glass. Place a stick of celery in each of the glasses. I cut about half an inch off the bottom of the stick too. Now celery takes quite some time, I left our sticks overnight. Carnations, I have known to give results within 2-3 hours. 

This was how they looked in the morning! :-) The pictures don't capture the green and the orange quite well, but they showed well. The red, obviously, displayed the maximum impact.

With carnations, the experiment ends here. You tell your little one how the water travelled up the stem and gave the petals the colour. Now I'll show you why I preferred the longer route with celery.

Cut the thick celery stem somewhere halfway and it will reveal tiny pores (xylem) all along its border. And yes, they would be tinted with the colours.. Literally, veins to carry blood.. err, water! You can also give the example of a straw for the same.

One more step further you go, and scrape off a bit of skin from the stem. You can actually see the straws (xylem)! The long tinted strands make it plain to understand how the water flows into the plant. This water travels up and is used to prepare food for the plant (photosynthesis).

Again, you make your choice on how to handle the verbal science talk. I personally did not bother with the scientific names. I was happy that it was plain to A that plants do take in water and it is essential for their growth.

In my experiment, you can notice that the leaves actually became quite dried and frayed through the 12-16 hours of the experiment. I used this to tell A that it could be because we did not expose the plant to sunlight - an essential component to make food for the plant.

So, did you find that interesting? :-)


  1. Oh wow. I want to try that right away. My daughter is too young for it now, but I will do it for myself this time ;)

  2. I've never seen this done with celery. Brilliant idea. I also like the ones with white roses placed in water with food coloring. Those can sometimes get quite beautiful. Elle @ Erratic Project Junkie

  3. That's such a wonderful way to demonstrate ... loved it :-)