Summer Science Fun: Do Leaves Breathe?

Sunshine, water, and leaves are not only the perfect ingredients for a summer day, but also almost all you need to demonstrate simple plant biology basics. These experiments start with one little question to ask your preschooler or kindergartener: “Do you think plants breathe?”

Bubbly Leaves

Grab a glass jar with a lid from the kitchen, fill it with water, and head outside on a sunny day. After your child selects a large leaf from a plant or tree nearby (which by itself had my five-year-old occupied for a while), drop it into the jar and close it. Place the jar in a sunny spot. After an hour, ask your child to look in the jar and report what they see inside.

Bubbles!

As oxygen is released by the leaf in the sun, many tiny bubbles form to show photosynthesis in action. While your kids are likely a little too young to understand much about the process, you can explain that it’s how plants turn sunshine into food and release oxygen for us to breathe. For more help talking—or singing—about photosynthesis, just ask They Might Be Giants.

Older kids might enjoy learning more about the science behind the experiment, or trying variations. What if the jar is left in the shade? What if you use a brown leaf in the autumn?

Original experiment found in Earth Science Experiments by Louis V. Loeschnig.

Capturing Leaf “Breath”

Not only do plants produce oxygen, your child might be surprised to learn they release tiny drops of water as well. While you’re waiting to go back and check on the jar of water, get a plastic sandwich bag and a rubber band or tape. Send your little leaf scout back out to find a small branch or clump of leaves.

Gently place the bag over the leaves and seal it with the rubber band or tape. After a couple of hours, check on the bag and see what’s inside. Your child will discover droplets of water captured by the bag. Plant “breath” has water much like our breath fogs up a window or mirror.

Want more know-how on the process? Read up on transpiration and be prepared for your preschooler’s persistent questions.