Have you ever wondered why pine cones open and close? Want to do a fun experiment to find out why? Why not give this experiment a go and try and predict the weather using pine cones.
This experiment works best by letting the children do the work. Start by asking questions such as why do you think pine cones open? How can we test it? What variable can we change?
To test why pine cones open and close you will need the following materials: 3 jars, 3 pine cones (the same size), warm water, cold water, a ruler and a timer.
First of all you will need to place a pine cone in each of the jars. (If you have younger children, you might want to use a plastic container for safety).
You then need to label each jar and fill with water. One needs to be filled with cold water, the other with warm water and for the third no water needs to be added as this will be used as a comparison.
Next you will need to sit back and watch carefully for any change. Note that the change can occur very quickly so make sure you do not leave it too late and miss out on any of the changes.
You may wish to keep a record of changes that happen- a good time period is to measure change every 5-10 minutes. You could create a story board and get your kids to draw the changes for each of the three different pine cones.
Try leaving the pine cone experiment over night to see if there has been any change?
Try experimenting with different temperatures of water to see if there is any change and use the experiment to try and predict the weather!
Predicting the weather
Another experiment that you can do with pine cones is to attempt to predict the weather. All you will need to do is place your pine cones on the window seal outside of your house. You may need to attach them with blue tack to prevent them from blowing away.
When the weather is dry the pine cones open up and when it’s going to rain they will close. It’s a really fun way for children to start to think about what the weather will be doing.
The Science bit:
Pine cones open and close depending on the humidity to help seed dispersal. Inside the pine cone there are lots of feather light seeds. When the weather is dry the pine cone opens up and any wind will catch the seeds and allow them to be dispersed in the air far away from the original tree.
When the humidity rises and rain is likely then the pine cone closes up to prevent the seeds escaping as being so light the seeds will become water logged and they will travel only a short distance from the original source which would be shaded and have to fight the “parent” tree for resources.