Closeup of leaves and their veins. Photo by Adam Przeniewski on Unsplash

Do leaves breathe?

  • Moderate
  • Not Messy
  • 15 Minutes
  • Indoor or Outdoor

Create an enviromnent to observe leaves breathing.

Plants use their leaves to recycle carbon dioxide and turn it into food for themselves and oxygen for us. In this experiment, create an environment where you can see this carbon dioxide/oxygen exchange happening!

You Will Need

  • Live leaf. Can be from any plant, just make sure it is freshly picked so it is actively photosynthesizing (i.e. do not pick it up off the ground)

  • Clear glass or plastic bowl that is large enough to fit the leaf

  • Water

  • Small rock

  • Magnifying glass (optional)

Directions

  1. Ask your child to carefully observe the leaf. What do they see? How does the leaf feel? Can they hear it breathing?
  2. Fill the bowl with room temperature water.
  3. Ask your scientist to place the leaf in the bowl of water.
  4. Then ask them to place the small rock on top of the leave to fully submerge the leaf under the water.
  5. Place the bowl in a sunny spot inside or outside.
  6. Wait for a few hours, then observe! Ask your young scientist what they see! (You should see small bubbles forming on the leaf and edges of the bowls. You can use a magnifying glass to take a closer look!)

How it works

Ask your kids what happens when they hold their breath, go underwater, and let their breath out. Likely they will say that they would see bubbles rising to the top of the water. That is similar to what you are seeing here!

When the leaf is submerged it is using light to continue the process of photosynthesis. Part of this process is to let oxygen out of the leaves. It is this oxygen that you are seeing as bubbles in the water. So while a plant does not breathe like we do (using lungs) it does take in and release air. You are “seeing” the invisible process of photosynthesis!

Key Words

Photosynthesis
The process plants use to make their own food, using sunlight, water, and carbon dioxide.
Stomata
Tiny gaps, mostly on the underside of leaves used by plants for gas exchange. Carbon dioxide enters the plant through these openings for photosynthesis and waste oxygen exits through these same openings.