My house always seems to be accumulating pinecones from the many large pines we have in our yard. Thanks to my mom’s nature collecting habits, we always have at least a basket of pinecones in our house, so I wanted to find a way to use them. Pinecones can be used as a hydrometer, which is a tool that measures levels of humidity. Pinecones close and open depending on the level of humidity in the air around them. You can easily turn them into a science experiment with just a bowl of water!
2 or More Pinecones
Step one: Go outside and harvest some pinecones, any kind work. I picked a few different types to experiment with.
Step two: Place your pinecones in a bowl, add enough water to cover 1/2 of the pinecones. Alternatively, you could use a jar and fully submerge the pinecone in water.
Step three: Let the pinecones sit in the water for an hour.
Step four: After letting them sit take them out, they have completely closed up. See how different the pinecones in low humidity vs the ones just submerged in water look!
Curiosities- What happened?
Pinecones can be used as hygrometers (a tool that measures humidity), they open or close based on humidity levels. Pinecones have very light seeds that need wind to carry them. Pinecones open up when humidity is low and close up when humidity is high. This is because when humidity is high and rain is more likely, this is not an ideal time for the seeds to spread as they can become heavy with water and unable to travel as far. When humidity is low it is an ideal time for seeds to spread, they can be carried by the wind easily since they will be light. In this experiment you can see that the pinecone closed up super tight because it was in water, acting the same as it would in 100% humidity.