Pinecone Science: See How Weather Effects Them

Did you know pinecones open and close because of the weather? Try this activity to watch it (slowly) happen before your very eyes!

(Photo via Adobe Stock)

Materials

• Pinecones

• A clear jar

• Water

Instructions

1. Fill a jar with water.

2. Submerge a pinecone fully in the water. Tip: To keep it completely underwater, you can fill the jar to the top and then cover with a lid, tie weights to the pinecone so that it doesn’t float to the top or put a plate on top or the pine cone.

3. Let the pinecone hang out in the water for several hours.

What happened?

The scales of the pinecone will close up tight! Pinecones hold seeds inside. When conditions are right — when it is dry and warm — pinecones will open up to release the seeds. But when it is too damp or wet, the pinecone protects the seeds by closing up the scales.

Pinecone scales are made up of many layers. The outer layer is more absorbent than the inner layer. When wet, the outer layers of the scales swell more. This causes the scales to curl inward, which closes the cone. The seeds won’t be released in bad weather!

Experiment further

Set a timer to see exactly how long it takes. Try with warm water instead of cold. Now take the pinecone out of the water to see if it reverses the effect. With the help of a trusted adult, put in the oven at about 350 degrees to see if it opens. How long does it take? See how much temperature affects times. Try different types of cones.

Male vs. female

What we think of as pinecones are female! Pinecones are how pine trees reproduce, or make more pine trees. At the top are the hard pinecones we know and love. They are female and hold the seeds. Pull back one of the scales. Look carefully at the base. You will see two seeds (or imprints of seeds if they were already released). At the bottom of the tree are male pinecones called catkins. They are soft and round, holding pollen that is like a powder. This pollen is carried by the wind to fertilize female cones on other trees. Neat!

Did you know?

Cones aren’t just for pine trees! All conifers are cone-bearing plants. In addition to pines, these include spruce, fir, hemlock and bald cypress. Many look a lot like pinecones. However, there are some cones that don’t look like their relatives.

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