Simple Pinecone Science – How Pinecones Open and Close

Want to impress your kids with a cool science experiment that’s also the EASIEST activity ever?

This pinecone science activity had my kids oohing and aahing despite its simplicity and super easy setup and cleanup. (Sometimes simpler really is better!)

All you need for this experiment are a couple of clear containers, water and ice, and some pinecones.

The Science of Pinecones

Most of us have noticed the different shapes and sizes of pinecones we find lying on the ground. In fact, some of these aren’t technically pinecones – which come from pine trees – but cones of firs and spruce trees. However, for the sake of simplicity, we will call all cones of conifer trees “pinecones.”

Next time you take a walk and pass pinecones on the ground, stop and take a closer look. Most of the cones we find on the ground will be open, which means the spines are splayed out, with space in between. Sometimes, though, you can find one that’s still closed, with the spines together in a tight cone shape.

So what makes pinecones open or close?

Try this simple experiment to find out.

YOU WILL NEED:

• Pinecones
• Clear Containers
• Cold Water
• Warm Water

STEP 1: Gather a few pinecones, preferably from different tree species. It’s nice to have a variety of sizes. The pinecones you collect will most likely be open.

STEP 2: Fill one clear container with cold water and ice cubes. Drop the pinecones into the cold water. You may see them close up immediately, but often the process will take a little while. Check on them every 5-10 minutes. Eventually, the cones should be fully closed.

STEP 3: Remove the closed cones and observe how different they look. Now drop them into the warm water and watch them open back up again! You can repeat this experiment over and over, and try different variables like varied water temperatures, pinecone species, and you can even try putting them outside on a hot or cold day.

See? I told you! Easiest experiment ever.

So why do pinecones do this? What’s the science behind it?

Inside each pinecone are seeds to make a new tree. The pinecone is actually the “fruit” of the conifer tree, protecting the seeds inside.

Pinecones open up to release their seeds when the weather is warm, and therefore the seeds will be released into favorable growing conditions. When it’s cold, the seeds are tucked safely away inside the cone until spring, when the seeds have a better chance of germinating.

Next time you’re out on a walk, or hiking through the woods, take note of the pinecones that are on the ground in your area. Are they open or closed?

And don’t forget – my Tree Anatomy Nature Study has ALL the fun activities and resources to learn about trees, bark, leaves and pinecones.

Tree Anatomy Nature Study