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Plant Needs: Water

Plan and set up an experiment to test if plants really do need water to grow


  • grass seeds
  • materials for an experiment, which will be determined by the group

Key Science Concepts

  • Plants need water to grow.


Emphasize science process words like experiment, test, and prediction, and plant words like seed, sprout, and soil.


  1. Ask children, What do you think plants need to grow and stay healthy? If children mention water, ask, How could we find out whether a plant needs water to stay healthy? What experiment could we do using grass seeds?
  2. Together, decide on an experiment (for example, plant two cups of seeds and only water one). Set up the experiment together and label it “Water Experiment.”

Reflect and Share

Discuss the experiment you set up together. Ask:

  • What do you predict will happen to the seeds? Why do you think so?
  • How will our experiment show if plants need water to grow or not?
  • Why do you think we set up the seeds in two different ways? What does it show us to do it both ways?

Have children draw a picture of the experiment.

One Week Later: What Happened?

Look at the results of last week’s experiment.     


  • drawings from water experiment
  • markers or crayons

Key Science Concepts

  • Plants have different parts: roots, stems, leaves, and fruit. 
  • A tree is a very large plant. There are many different types of trees.


Encourage children to use science process words such as experiment, observe, describe, compare, predict, and results.


Remind children that it’s been about a week since you set up your experiment testing whether seeds need water to grow. Have children look back at their drawings of the experiment. Explain that it’s now time to look at the results.

As you observe the results, ask someone to explain the experiment. One cup of seeds received water and the other did not. Ask: 

  • What do you notice about the grass seeds?
  • What happened to the seeds that got water? What happened to the ones that didn’t?
  • What do you think we learned from this experiment?

Finish by having them draw pictures of the results.

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