Do sunflowers follow the sun?

Along the path by the visitor centre at Frampton Marsh we have sown a wildflower mix strip. When it’s grown up this will be a fantastic place for butterflies and bees, as well as looking very beautiful. Some of the flowers included are perennial flax, black mustard and sunflowers. The latter have been looking great recently, and are really growing quickly.

Now I’ve always been told that sunflowers rotate during the day in order to face the sun, there are numerous quotes about it. But as I’ve found out this is only partly true. Young sunflowers do track the sun, following it from east to west and then back again to await the sun. This movement is due to uneven growth, one side of the stem growing longer during the day and the other during the night. When they become adults they settle and face east, these sun following behaviours when they are young have been shown to result in bigger plants than those who did not follow the sun. The adults that face east also are found to be warmer, which helps them attract bees and other pollinators.

Sunflowers have been a source of endless fascination and they pop up everywhere. Here are a few interesting facts about sunflowers. They are the subject of a series of painting by Vincent Van Gough (one of which 'three sunflowers in a vase' is shown below); they were worshipped by the Incas as they believed them to be a symbol for the sun and they are the national flower of Ukraine.

There is also something quite interesting about the flowers in the centre of the head, the ratio of the spirals in the head of the flower are consecutive numbers in a series called the Fibonacci sequence. The sequence works by adding the previous two numbers together (0,1,1,2,3,5,8,13,21,34,55). Sunflowers usually have 34 spirals in one direction and 55 in the other direction. The purpose of the alternating spirals is to pack as many in as it can, as efficiently as possible.

Hopefully as the flowers grow and the strip matures we will see many more interesting things growing before too long, it’s always worth a closer look.