Clear plastic sandwich baggies
1. Select a few plants with clusters of leaves that can easily be reached.
2. Place a plastic bag around the cluster of leaves and secure with a twist tie.
3. Allow the bags to sit for a few days and record your results over time.
What Happened and Why?
Plants undergo a process called transpiration, whereby water moves through the plant. Leaves contain tiny pores through which the water evaporates. The water droplets that accumulated in your bag are the result of the plant “exhaling” or eliminating water from its system in the form of evaporation.
If you selected a variety of plants and trees, you may notice that the ones with larger leaves tend to accumulate more water. This is because larger leaves transpire faster than smaller leaves. On sunny days, you may have noticed your subjects transpired more than they did on cloudy days. Light tends to encourage the leaves’ pores to open, which increases the amount of evaporation.