I’m sharing today about a super fun, yet ridiculously simple, science experiment you can do at home or in class with your littles – with minimal supplies and mess. This little nature trick is so simple, but prepare to have your mind blown!
(This experiment comes from the Tree Anatomy Nature Study – check it out here!)
Pinecone Science: How Pinecones React to Environmental Changes
What you’ll need:
- Large container (a glass bowl or clear plastic one is best)
- A variety of pinecones, preferably with scales open (feel free to pinecones from different trees)
- Cold and hot water
Yup – that’s it! Told you it was easy.
First, take a look at your pinecones. Most, but not all, pinecones you find on the ground will have their scales open. Observe them closely and notice their size and shape, and look closely at the scales.
Next, fill your container with ice cold water. We used cold water from the sink and dropped in a few ice cubes.
Set one of the pinecones aside next to the bowl. This will act as your control group.
Now, ask your students what they think will happen when the pinecones stay in the cold water. Drop each one into the water (they will float).

Take a few minutes to watch them closely. You may notice some changes happening right away – take note of this.
Come back in 5 minutes to observe your pinecones. Are the scales closing up?
Check them again in 15-30 minutes (depending on your water temperature, you may have to wait longer). Your pinecones should be nearly closed or all the way closed up. Remove them from the water and take a closer look. You can compare them to the control group if you wish. They look totally different, right?
Now, dump the cold water and fill the bowl again with hot (not boiling) water. Once again, place the pinecones in the water and watch as they open back up!
The Science Behind It
This little experiment looks like magic but it’s simple science!
Hidden behind the scales of a pinecone are small seeds to grow new trees. In nature, pinecones must open order to release their seeds. The scales of pinecones open and close in response to changes in humidity and temperature. When the air is warm, pinecones open to release their seeds. The warm weather means the seeds have a better chance to germinate and grow into new trees. When it’s damp and cold, they close up.
*Note: The term “pinecone” refers to the cone of the pine tree, but I’m using it loosely here to refer to the cone of any conifer (cone-producing) tree.
Want more tree science, activities and experiments? Check out the Tree Anatomy Nature Study!


