Why sunflowers turn toward the sun: this is the reason

The sunflower got its name precisely because its flower head turns with the sun's position as it grows. In the early morning it faces east to greet the sunrise, during the day it gradually shifts westward, and at night it slowly turns back to the east, so that when the sun rises the next day it once again faces east. This phenomenon of turning with the light is generally called heliotropism in botany, and it is a typical light-sensitive movement.

This phenomenon mainly occurs during the young growth stage of the sunflower. It is generally believed that the two sides of the sunflower stem grow at different rates: the shaded side accumulates more auxin, its cells elongate faster, and this pushes the flower head toward the sun, making it look as though it is chasing the sun. In addition, this turning rhythm is also related to the plant's internal biological clock; even on a cloudy day without sunlight, the sunflower will continue to turn according to its own rhythm.

Once the sunflower has fully bloomed and matured, the flower head basically stops turning, and most will fix their orientation toward the east. For the plant, following the sunlight allows it to receive more ample light, enabling the leaves to carry out fuller photosynthesis and accumulate more nutrients; facing east in the morning also lets the flower head warm up faster, making it easier to attract bees and other insects for pollination, which is very helpful for seed formation later on.

It should be noted that a sunflower does not follow the sun for its entire life; the orientation of the flower head changes with its growth stage. When growing them at home, choose a spot with ample light and good ventilation, and water and fertilize in time, and they will grow upright with full flower heads, giving better results whether for ornament or for harvesting seeds.