Hatching new scientists every day!

Plant Needs: Sunlight

Set up an experiment to test whether plants need light to grow.


  • grass seeds
  • paper towel
  • plastic sandwich bags
  • paper plate
  • bucket (optional)

Key Science Concepts

  • Plants need light to grow.


Emphasize science process words like experiment, test, compare, describe, observe, and prediction.


Ask children, What do you think plants need to grow and stay healthy? Then say, Let’s set up an experiment like the children did in this morning’s video to find out if plants need light to grow. Ask them to describe how children in the video set up the experiment. Then have the group set up one experiment together.

  1. Fold two wet paper towels and add each to two plastic bags. Add grass seed to the bags and seal.
  2. Put a paper plate on top of one of one of the bags, blocking light from reaching the seeds. Leave the other bag exposed. Place in the Watch Them Grow center and label “Light Experiment.”


You may also try putting a bucket upside down on a grassy area outside. Ask children to check periodically to see what happens to the grass underneath the bucket. 

Reflect and Share

Ask children:

  • Why did we set up two different bags? What is different about the two bags? How might this experiment show us whether seeds need sunlight to grow?
  • What do you predict will happen?

Have children document the experiment in their Plant Journal. (They might draw a line through the middle of the page. On one side they could draw the seeds receiving sunlight; on the other, the seeds covered by the plate that won’t get sun.)

Looking at Results

Next Thursday you’ll look at the results of the experiment together. Talk about how many days away this is by looking at the “Our Plants” chart and counting the days until Thursday.