1、 Why does sunflower always face the sun

Sunflowers always face the sun, mainly because they are affected by light. As soon as it meets light, it will rotate with the sun. However, generally during the period from germination to flowering, its leaves and flowerpots will rotate with the sun. After the flower plate is in full bloom, it will be fixed towards the East.

The rhizome of sunflower contains a kind of "plant auxin" which can avoid light and stimulate cell growth. When this auxin encounters sunlight, it will run to the side of the backlight to avoid it, which will accelerate the growth of the backlight surface and slow the growth of the sunny surface, so that it can grow towards the sun. Specifically, because most of its auxin is distributed on the backlight surface, while the auxin concentration on the sunny side is low, which makes the backlight surface grow faster and the sunny side grow slower. In this way, the light bending of the stem is caused, resulting in the phenomenon that it has been growing towards the sun.

2、 How do sunflowers turn their heads at night

The leaves and plates of sunflowers follow the sun from east to West during the day, not immediately. Botanists have measured that the direction of its flower disc will lag behind the sun by about 12 degrees, or 48 minutes. After the sun sets, auxin will be redistributed, and the sunflower will slowly return to its starting position and face the East again. Around 3 a.m., it will face east and wait for the sun to rise.