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Window Greenhouse (Ages 5-8)

November 07, 2019
Project created in collaboration with the educational experts at KiwiCo to promote STEM learning and creative confidence.

How do plants grow? In this experiment, you will create a mini greenhouse to learn how plants depend on sunlight and water.

How do plants grow? In this experiment, you will create a mini greenhouse to learn how plants depend on sunlight and water. Place seeds in a Ziploc® brand sandwich bag with a wet paper towel and put the bag by a sunny window. Record your observations daily to see how long it takes for the seeds to sprout and grow leaves. What do you observe?

Learn more:

When the seeds have sun and water, they sprout. But do they need both sun and water? Make multiple window greenhouses and test it out! What happens if you place the seeds in a dark room with water? Or in a sunny spot without water? Or even in a dark place with no water? What do you see?

Connections with Next Generation Science Standards (NGSS)

Ecosystems: Interactions, Energy, and Dynamics 2-LS2-1.

Plan and conduct an investigation to determine if plants need sunlight and water to grow.

Create a window garden that shows how sunlight and water help plants to grow, then experiment further to test the effects of each variable.


  • Small bowl
  • Handful of seeds or 3 larger beans
  • Water
  • Scissors
  • Paper towel
  • Construction paper
  • Tape


  • 1 Gather your materials.
  • 2 Cover the seeds with water. Soak them overnight. (Soaking the seeds will help them sprout faster.)
  • 4 Dampen the towel. Gently wring it out so that it’s still damp but not dripping
  • 5 Place the damp towel inside the bag
  • 6 Place a few seeds on the paper towel inside the bag, an inch or two from the bottom
  • 7 Lay the bag on a sheet of paper and sketch a house shape around it. Cut out the house shape, then cut out a window for the bag to peek through. Make sure the window is large enough to see all your seeds, with room to grow! If you want, draw on the greenhouse with markers or decorate it with paper cut-outs.
  • 8 Tape the bag and frame to a window, with the seeds facing inside so that you can see them sprout. Keep track of how your seeds grow with our Observation Journal Printable! If you like, create more greenhouses and let them grow under different conditions or locations to observe what happens. Print additional journal pages to track their progress.