There is little in nature that is more picturesque than a glorious field of sunflowers, a sea of golden blooms majestically soaking up the sun as far as the eye can see. One of the more notable features of the sunflower is how it follows the sun from east to west during the course of a day while it grows. New research published in Science magazine has shed some light on how and why sunflowers follow the sun.
How? Growing One Side at a Time
The sunflower is able to turn its head from east to west and back again by alternating which side of the stem grows. The east side of the stem grows more during the day and very little at night while the west side of the stem is just the opposite, growing more at night and very little during the day. These growth patterns are controlled through a combination of circadian rhythm and light sensitivity turning certain growth genes on or off.
Researchers noted that the sunflowers that were allowed to follow the sun normally in their study were about 10% larger. Once the sunflower matures it stops growing from side to side and winds up facing east. This is not by accident though as east facing flowers attracted 5 times more pollinating insects than west facing flowers.
The video below from the Washington Post does an excellent job of illustrating the process.