Intro: Gardening Science: Investigating Germination
The germination of seeds is a perennial* subject in science classes around the world.
Seeds are planted somewhere, they germinate, the students look at them.
The hard part is looking at what you are growing.
The point of this project is to provide students, teachers and interested parents with a starting point for investigating the germination of small seeds, in a way that makes them easy to see and record, using reclaimed hardware.
Step 1: Such a Complicated Set of Equipment...
You need an old "jewel" CD case*, some paper towel or tissue, and some seeds (these are poppy seeds we harvested a couple of years ago).
*You'd be amazed how much science can be done with recycled scrap!
Step 2: Preparation
The CD case has a "liner". You should be able to prise it out with your fingers, but, if your nails are very short, you may need a small blade to get between the inner and outer parts.
Pull out the liner, and discard it and any labels responsibly. Depending on your local waste disposal services, both should be recyclable.
Step 3: Growing Medium
You need something to hold the seeds in place.
The easy way to do this is with a pad of tissue paper or paper towel, pressing the seeds against the CD case lid. The amount you need depends on the thickness of your paper - I needed two paper towels, folded into eight, with a little trimmed off the end.
Make sure you put the towel in the end away from the gap left by the liner.
Step 4: Just Add...
...whatever you need.
I dampened the towel with tap water, and laid the poppy seeds in a line, because all I am testing here is whether the seeds will germinate, or be fed to the birds.
Step 5: The Science Bit
For such simple equipment, there is a lot of good science you can do, as long as you have a number of CD cases.
- Investigate the ideal amount of water needed for germination.
- Investigate the best temperature for germination.
- Investigate what happens in different lighting conditions (especially after germination) - different amounts, colours and directions).
- Leave one in your car door pocket to see if vibration affects germination.
- Dissolve different amounts of fertiliser in the water.
- Once the seeds germinate, try turning the cases over for different amounts of time to investigate the effect of gravity on plant growth