May 8, 2014

Growing Bean Seeds

Kindergarten Sun Unit Study

Growing bean seeds with a variable - a simple science experiment to demonstrate why we need sunlight.

The other day I shared that I have started kindergarten with J-Bug (5) and why we love My Father's World Kindergarten.  Continuing with our study of the sun, I set up a simple demo to demonstrate how the sun gives life.  This demonstration took a little over a week and required a bit of patience since it involved growing bean seeds.

How does the sun give us life?  A hands on activity to demonstrate the importance of sunlight.

How to Grow Bean Seeds

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To demonstrate why the sun is necessary to grow seeds and plants J-Bug and I selected two bean seeds and two jars.  J-Bug filled each jar with water then dumped it out to get the jar nice and moist and ready to host a seed.

I carefully folded a paper towel and put it inside each jar, pressed against one side.  J-Bug added a bean seed to each, using care to leave it between the glass and the paper towel.  The towel absorbs the moisture in the jar and gives the seed the water it needs.

We left one jar on the windowsill in our kitchen where it gets plenty of sunlight.  We hid the other jar in the pantry, away from any light.  We checked on our seeds every other day and added a small amount of water to the bottom of the jar.  J-Bug was in charge of adding the water. 

After two weeks, can you guess what our seeds looked like?  I explained to J-Bug how important it is to only leave one variable when doing a science experiment and keeping everything else the same.  When one seed got water, the other seed got water.  The only variable was the exposure to or lack of sunlight.  I wish I would have had the camera ready when J-Bug saw his seeds after a long weekend away at Grandma and Grandpa's house!  Of course the seed that had been on the windowsill had sprouted and was really taking off, while the seed kept in the dark had not grown at all.

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Simple science experiment to demonstrate how the sun gives us life

More activities for a sun unit study:

 How to make raisins - simple sun science for kidsHow to make a sundial - hands on activities to learn about the sun


  1. This is a cute idea, but the science is a little off. The seed doesn't actually need the sun, it just needs water and heat to germinate (sprout). Once the seed has germinated, it needs the sun to continue growing. You can demonstrate this with a "pocket bean" - put the bean and wet paper towel in a small plastic baggie and keep it in your son's pocket. It will start to sprout a root in just a day or two. Once the seed has grown a bit in your pocket, you could start your experiment as you described above, and you will see that the seed in the windowsill continues to grow while the seed in the pantry eventually stops growing. This is because the seed has energy from the sun stored inside it. It can start growing with this stored energy, but eventually uses up its stored energy and needs energy from the sun to continue growing.


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