NEXT: Crestmead

Seed Germination

Seeds aren't such tough nuts to crack. See what really makes them grow

Australian Curriculum links

  • Science > Biological Sciences > Year 1 > ACSSU017
  • Science > Biological Sciences > Year 1> ACSSU211
  • Science > Science as a Human Endeavour > Year 1 > ACSHE021 & ACSHE034
  • Mathematics > Measurement and Geometry > Year 1 > ACMMG019
  • Technology > Food and fibre production > Year 1 > ACTDEK003

You’ll need

  • Plastic containers/cups/trays or seed trays (can be plastic takeaway containers with holes drilled in the bottom). Toilet roll inserts can also be used.
  • Water-tight tray to hold seed containers
  • A range of seeds
  • Cotton wool
  • Sand
  • Soil
  • Potting mix
  •  

Try this

  1. Collect seeds from your local environment (in temperate or sub-tropical climate this is best done in autumn) and fruit. You can also collect seeds from the spice or legume aisle in the supermarket. Bird seed mixes provide a range of seeds.
  2. Describe the seeds, e.g. light, small, pointy? Can you identify any of the seeds? For the seeds that you can’t identify, make a guess about what type of plant the seeds might grow into and record their guesses.
  3. Identify a place for seeds to grow undisturbed where trays are not exposed to extremes of temperature or light.
  4. Plant one of each type of seed in the potting mix and record the seed name on the container or on an icy-pole stick.
  5. Record the growth and appearance of the seeds and seedlings over five weeks. As seeds grow, record how quickly they grow, when the first leaves appear and how many. Do big seeds grow bigger plants?

Further investigation

  • Once you have identified seeds that grow well, you might like to investigate other variables in the growing process:
    • Try using materials other than potting mix for raising the seeds. This might include include polystyrene balls, gravel, packing peanuts, charcoal or cotton wool. Which medium do the seeds grow best in?
    • Try placing a tray of seeds in varying levels of light e.g. one in a sunny window, one away from windows and another group of seedlings in a cupboard. How will light affect the seedling growth?
    • Try changing the temperature of the water you pour on the seedlings. Use ice cold water for one group, room temperature water for another and boiling water for another group. Do you think water temperature will affect how the seeds grow?
  • Test the properties of the seeds before planting them. What happens when they fall? Do they fall quickly or float lightly? Do the seeds float? Are their shells strong? Can you squash them?
  • Which plants do you like at home? If you made a small herb box, where would you put it?

What’s Happening?

Seeds are unique and adapted to a range of environments. Some seeds need to survive a cold winter and need cold weather before they germinate. Others need the heat of bushfires to germinate. Some plants grow in dark forests and germinate in the dark, others need strong sunlight.

If all seeds grew where they fell from their parent plant, then these areas would become very crowded and it would be harder for all the plants to grow. This is why seeds have developed into very different shapes. Some attach to the fur of animals and others are carried by the wind. ‘Helicopter seeds’ use their unique shape to float gently away from their parent. When was the last time you ate some fruit? What did you do with the seeds? Some plants encourage animals to eat their fruit and spread their fruit that way.

Real world links

Seeds can survive all sorts of extreme conditions. A date palm was germinated from a seed found in an archaeological expedition in Israel. The tree grew metres tall from a seed that was at least 2000 years old. If you think that is impressive, Russian scientists germinated a plant from a seed that was thought to be over 30 000 years old. The seed had been buried by an ancient squirrel so that it had something to eat over the cold winters. A flood had blocked its access, sealing the seed away until scientists found it in 2007.