Transpiration Experiment

Water, water, everywhere— even coming from the leaves! Check out this science experiment in your own backyard to learn about a key part of the water cycle: transpiration. Transpiration is the process of plants releasing water through their leaves (through pores called stomata). With this experiment you can capture that water and make comparisons between leaves in the sun or shade, differing kinds of leaves, or even leaves that are on versus off the plant!

All you need are plastic bags, and a plant with leaves or needles. For guidance through a comparison of the transpiration rates of different types of leaves, check out our downloadable experiment guide. Or try your own creative transpiration experiment: compare different sized leaves, compare different color leaves, compare leaves in the sunlight versus the shade… the possibilities are endless!

Downloadable experiment guide: Transpiration Experiment

To tie your experiment back into the water cycle, consider these questions:

What parts of the water cycle can we identify?

Where did the water on the bag come from?

What caused the plant to release the water?

Is the plant transpiring when there is not a bag on it to capture the water vapor? Why or why not?