Are Sunflowers Intelligent?

By David Wall
Guest Columnist

We’ve previously discussed plant intelligence being on a different level than most of us understand, and sunflowers seem to be a good example.  Many sunflower varieties are noted for an ability to follow the sun from dawn to sunset, before turning around overnight to face east for the next sunrise.

Numerous tests have appeared to indicate that some form of intelligence is involved.  Tying plants so they couldn’t rotate caused slower growth compared to those that could rotate.  Similar tests growing sunflowers in pots rotated to face away from the morning sun also resulted in growth reductions.

In another test, sunflowers were grown indoors in a closed, unlit facility under artificial light.  By using the lights rotationally, 30-hour day was created, but the plants refused to rotate.  When they switched back to a 24 hour day, plants began rotating again.

These tests raise the question as to whether sunflowers can tell time as well as whether they can sense direction.  While this may be some aspect in instinct we don’t understand, it also raises the specter of plant intelligence that we also don’t understand.

Interestingly, once sunflowers begin blooming, they stop rotating and just face east.  So, what happens if the plants are rotated so they face west?  The plants don’t rotate back to the east, but the plants facing east are visited by pollinators at a 5-1 ratio over plants facing west.  While on the surface, this makes no sense, researchers are well aware that east-facing plants warm up faster than west facing plants, and warmer flowers attract more pollinators.

Do plants – sunflowers specifically – have intelligence rather than some form of instinct, neither of which we understand?  I don’t know, but I do talk nicely to my vegetable plants and apologize if I break off a leaf or stem!!!