Plant Science for Kids: Plants and sunlight

plants and sunlight experiment for kids

Our summer gardening experiment has led to several questions about plants. I explained that plants get energy from the sun, and designed this simple experiment to teach my kids how important the sun is to plants.

Plant Science for Kids: Plants and sunlight

For this experiment, we put a tomato seedling in front of a window, and observed that it bent its stem to expose its leaves completely to the sun. Then we marked where the leaves were leaning using a marker (see the right edge of the pot), and turned the pot so that the plant was facing away. We did this several times, noting each time that the plant would change directions to get as much sunlight, and always marking the edge of the pot that the leaves were closest to. It’s an experiment I hope to repeat with my kids over the years, explaining what is going on in greater complexity as they grow older.

Here are a few adaptations for older kids:

  • Ask them to predict what, if anything, will happen to the plant after it is moved in front of the window
  • Once the plant moves, ask them to explain why

There are also some great picture books you can read to go along with this experiment, for example:

*Note: these are affiliate links, and I may earn a small commission at no cost to you if you purchase a book using these links. Thank you for supporting my site!

Do you have a favorite plant science picture book that I should I add to my list?

The experiment definitely made an impression on Emma – she has been drawing plants in the sun ever since, like this:


The little animal on the top right is a bumblebee, pollinating the flowers =)

tomato seedling following the sun

What are your favorite experiments and other science activities for kids?


  1. Jaimie says

    This is such a great idea. It’s one of the things that has always fascinated me personally about plants (that they can actually move, and quickly!), but I’ve never thought to point it out to my kids. I can think of so many ways to illustrate this now. Thanks for sharing.
    .-= Jaimie´s last blog ..Self Portrait Saturday 8- July 17th- 2010- Almost Two Years Ago =-.

  2. says

    That’s such a fun learning opportunity. We did something similar when my daughters brought home potted sun flowers from school. They kept asking why the flowers were “bending to the window,” which led to a discussion about why the sun is important for plants.
    .-= Quadmama´s last blog ..Our Mini-Vacation =-.

  3. Valerie @ Frugal Family Fun Blog says

    Love her drawing! Sounds like she is really understanding the concept quite well. We just read Leaves, Leaves, Leaves and Emily really enjoyed it.
    .-= Valerie @ Frugal Family Fun Blog´s last blog ..Super-Easy Cool Comets =-.

  4. says

    I thought it was a rake at first :) This is a great experiment, and I always enjoy seeing Emma’s drawings.
    .-= Natalie´s last blog ..Geography Track – Landmarks =-.

  5. maryanne says

    Thanks everybody! And Natalie, I can see why you thought it was a rake – I was a little surprised when she said they were flowers ;)

  6. says

    I just wanted to tell you that I really enjoy your blog. I came upon it sometime last year and I keep returning to see what’s new. You children are adorable by the way. I love your crafts, they are unique.
    .-= Tiyana´s last blog ..Homeschool – Unschool =-.

  7. Solana says

    I’m doing thus with my preschoolers. One set of 8 in the class closet, one set of 8 outdoors. We planted sunflower seeds. 5 days later, 6 of the seeds in the closet sprouted. The entire set outdoors did not show any signs of “poking” through the soil. By the end of the week, the set in the closet was standing 4-6″ strong. One seed from the outdoor set had just poked through. What are your thoughts? I’m shocked.

    • maryanne says

      Is the closet warmer? It’s definitely more climate controlled, which might help sprouting. The plants only need light to thrive once they have leaves, so as time hours by your outdoor plants will probably do better, would be my guess. Does that make sense?


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