How to measure and count your sunflowers

When your sunflowers are ready to count you will need a few items to help you to count...

  • Some items you will need - tape measure, pen, smartphone, step ladders, scissorsa waterproof pen (in case it rains)
  • some tape to label each of your sunflowers
  • some string
  • a tape measure - at least 2-3 meters
  • an adult to help out
  • step ladder
  • a digital camera or cameraphone
  • a video camera to record your video diary for this stage

Other things that might help...

  • Turing's Sunflowers Counting Guideour counting guide to show you what to count and to write your data on
  • the seed name (cultivar) that you grew (check the seed packet) - don't worry if you can't remember the name

Step by step guide

The important data we want you to submit are:

  • the spiral counts in both directions (clockwise & anti-clockwise)
  • seed head diameter

All the other data that you submit is a bonus

  • How to count the number of bractsnumber of petals
  • number of bracts
  • height of sunflower
  • leaf data

Watch Marieke show you how to collect the data we need to make your sunflowers count towards the experiment.

How to harvest and measure your sunflower

  • How to measure the width of the seed headIf you have more than one sunflower, label it so you know which one's which
  • Measure the height of your sunflower in centimetres by measuring from the middle of the head to the soil where the roots begin
  • Measure the width of the sunflower head in centimetres
  • Use scissors to cut off the seed head about 5cm down from the top of the stem (get an adult to help with a ladder if needed)

How to count the spirals in the sunflower seed head

  • Have a look at the diagrams on the right
  • Use a camera to take a good picture of the sunflower head with the spiral patterns clearly in focus. You will need to upload this later.
  • Either print out the picture to mark on the spiral patterns with a pen or use tweezers to pick out a line of seeds from every tenth spiral.
    How to count the anti-clockwise spiralsHow to count the clockwise spirals
  • Count the spirals in both directions - did you get Fibonacci numbers? (0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144...)
  • Add the two spiral counts together - is this a Fibonacci number too?
  • If you didn't get a Fibonacci number, don't worry it's still important for us to know what you get.

Once you have collected your data, register your sunflowers to submit the data.

Taking a photo of your seed head

In order to check our results, we really need to see a good photo of your seed head so we can count the spirals and look out for any really interesting examples. Most digital cameras and smartphones have good enough cameras for what we need, but it's really important that the picture you take is in focus, is straight on and includes the whole seed head.

Here's a couple of examples of photos that we wouldn't be able to use...

This photo is taken from an angle - we need to see the seed head straight on
This photo doesn't show the whole seed head, so we can't count the spirals

Taken straight on, in focus and showing the whole seed head - the photo below is perfect for what we need:

A whole seed head photograhed straight on and in focus