Why do mature sunflowers face east?
Quick Answer
Young sunflowers track the Sun across the sky, but once they bloom they stop and face east, which warms the flower heads in the morning and attracts more bees.
The Full Story
Growing sunflower plants follow the Sun from east to west during the day and swing back east overnight, a behaviour called heliotropism controlled by their internal circadian clock. As the plant matures and the stem stops growing, the flower head settles facing east. A 2016 study in the journal Science by researchers at UC Davis found that east-facing heads warm up faster in the morning sunshine. Warmer flowers attracted about five times more pollinator visits than west-facing ones. So facing east is a strategy to win the attention of bees early in the day.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Sunflowers don't follow the Sun forever — the clever reason they all end up looking east."