Fact Check: Why Sunflowers in These Videos Don't Face the Sun

In early August 2024, a viral TikTok made the bold claim that "something just isn't right with the sun anymore." The post's evidence? A patch of sunflowers, known for turning their flowers throughout the day to follow the sun in the sky, were facing away from the sun. Snopes found several other videos documenting the same phenomenon dating back several years.

Although the posts did not always draw conclusions about the behavior of the sunflowers, the underlying implication was that it was not natural, and a large scale conspiracy was at hand. Some users suggested that the sun had been replaced with an artificial light, and that the sunflowers were actually following the "real sun." This claim was supported by other users commenting that "nature is constantly giving us signs," that they were tanning differently, that they had noticed the sun's color had changed from yellow to white and theorizing that the April 2024 solar eclipse could have somehow been involved.

However, using the sunflower's "strange" behavior as evidence for a large conspiracy doesn't work if the behavior isn't strange in the first place. As it turns out, sunflowers don't always turn to follow the sun, contrary to popular belief.

The turning behavior is called heliotropism , from the Greek for "sun" and "turn," and although it's mostly associated with the sunflower (scientific name Helianthus annus), botanists have observed and recorded it for a long time , in many different plants. But whether the sunflower truly follows the sun has been debated for just as long : herbalists back in the 1500s also questioned whether the behavior was real.

The truth of the matter lies somewhere in between: While juvenile sunflowers do follow the sun in the sky throughout the day, the behavior stops once the sunflower reaches maturity.

A research group at the University of California, Davis discovered that just like humans, sunflowers have internal alarm clocks, called a circadian rhythm, that allow them to make changes based on the time of day. While humans generally associate circadian rhythms with our sleep cycles, juvenile sunflowers use their circadian rhythms to track the sun.

According to the group's research , a juvenile sunflower follows the sun by growing only one side of its stem depending on the time of day. When the sun is out, the plant's stem grows more on the eastern side, pushing the head of the flower towards the west as the sun moves in that direction. During the night, the plant's stem grows more on the western side, pushing the head of the flower back towards the east, where the sun will rise in the morning.

However, once the sunflowers reach maturity, their circadian rhythm changes to strongly favor the early-morning light. So, the flowers settle down and always face east to capture the morning sun instead of following it in the sky.

So, no, the sun hasn't been replaced. The sunflowers in the viral videos are mature sunflowers, not juveniles. Although those sunflowers used to track the sun in the sky, they stopped upon reaching maturity to face east.

Sources:

Extension | What Is Heliotropism? 1 June 2021, https://extension.wvu.edu/lawn-gardening-pests/news/2021/06/01/what-is-heliotropism .

Fell, Andy. "How Sunflowers See the Sun." UC Davis, 31 Oct. 2023, https://www.ucdavis.edu/curiosity/news/how-sunflowers-see-sun .

---. "Sunflowers Move by the Clock." UC Davis, 4 Aug. 2016, https://www.ucdavis.edu/news/sunflowers-move-clock .

Kennedy, Merrit. "The Mystery Of Why Sunflowers Turn To Follow The Sun — Solved." NPR, 5 Aug. 2016. NPR, https://www.npr.org/sections/thetwo-way/2016/08/05/488891151/the-mystery-of-why-sunflowers-turn-to-follow-the-sun-solved .

Lang, A. R. G., and J. E. Begg. "Movements of Helianthus Annuus Leaves and Heads." The Journal of Applied Ecology, vol. 16, no. 1, Apr. 1979, p. 299. DOI.org (Crossref), https://doi.org/10.2307/2402749 .

Vandenbrink, Joshua P., et al. Turning Heads: The Biology of Solar Tracking in Sunflower. July 2014. escholarship.org, https://doi.org/10.1016/j.plantsci.2014.04.006.