Grow a Sunflower Science Experiment

Plant sunflower seeds between August and January and watch them grow into tall, bright, beautiful living sun trackers. Challenge friends or classmates to find out who can grow the tallest!


What you need…

  • Sunflower seeds
    There are lots of sunflower species. Ask at your local garden centre for the sunflower that is best for what you want and where you live.

  • Compost soil

  • Small starter pots
    Plastic yoghurt pots are a great option - just get an adult to put drainage holes in the bottom for you.


CAUTION: Gardening gloves and face masks are recommended because compost soil can sometimes be toxic.


What to do…

  1. Fill up your starter pot with soil.

  2. Make a dip in the soil about 2.5 cm deep with your finger and put the sunflower seed inside, covering it with soil*.

  3. You can put in a label to help you and others remember that your sunflower is growing there.

  4. Water your pot whenever the surface of the soil feels dry

  5. Within about 7-10 days your sunflower should have grown into a seedling.
    Make sure your sunflowers get 6-8 hours of direct sunlight every day and water them several times a week.
    Enjoy watching each stage as the sunflower grows taller.
    If you choose to plant them in your garden, position your sunflowers in full sun and space plants 20-30 cm apart.

Things to consider…

  1. Think about Size: You can carefully plant your flower outside in a sunny space sheltered from the wind. If your sunflower species is one that grows very tall you may want to plant it next to a wall for support or perhaps use a wooden steak to give it support.

  2. Think Ahead: We recommend you plant more than one seed. We planted this one and also filled a gardening tray with the rest of the seeds. Some seeds may not germinate well so it’s good to increase your chances.

  3. Think of Food: SOME sunflower seeds are edible, these species are great for us or for birds. Let the flower die on the stem and harvest the seeds from the middle of the flower ready to enjoy!


Fun Facts about Sunflowers…

  • Sunflowers are heliotropic so they follow the suns path.

  • Guinness World Records awarded the world record for the tallest sunflower to Hans-Peter Schiffer in Germany, on 28 August 2014. His sunflower measured 9.17 meters!
    How tall can you grow your sunflowers?

  • Vincent Van Gogh (a famous Dutch painter) did a series of paintings featuring and called Sunflowers.

  • Sunflowers are large inflorescence, this means the flower head is actually made of many tiny flowers called florets.


About the sunflower lifecycle…

  • Seed to Shoot
    After the dormant (sleeping) sunflower seed is planted it needs water and warmth as well as soil which will help it to germinate. When a seed germinates small roots will begin to grow from it.
    After about 7-10 days a shoot will grow out of the soil in search of sunlight and leaves will begin to grow from the stem. At the same time, the plant will grow roots in the soil absorbing nutrients and water for the plant.

  • Bud to Bloom
    With enough sunlight, water and nutrients the seedling will continue to grow and a bud will form which will eventually begin to open and then fully bloom.

  • Death and New Seeds
    When sunflowers die the whole plant shrivels and the seeds in the centre of the flower are released ready to grow new sunflowers.


Did you grow your own sunflower?

Send us a photo of your sunflower and you might find your photo featured in a future issue of Upstart magazine OR on Upstart online… AND win a prize!