Our Plants Need to Sleep Too!

Recently, I have noticed that my Episcia (aka Flame Violet) often folds up its top pair of leaves when the night comes. The leaves are near the horizontal during the day and close to the vertical at night. And while sometimes the pair of leaves moves just slightly, pointing to the ceiling, there are times the leaves fold up so tightly, sticking against each other with hardly any gap in between.

As ignorant as I may sound, at first, I suspected that this movement of the leaves of my Episcia was due to insufficient sunlight (it had been rainy and gloomy for over a week). So, to keep my Episcia “open” at night, I put my plant under artificial light for around 14 hours per day for several days. However, the artificial light didn’t help at all. The top pair of leaves closes at night regardless of the amount of light there is during the day.

Plant Chronobiology - Flame Violet Plant Chronobiology - Flame Violet

My baby Flame Violet, which I have propagated a while ago, also has its own circadian rhythms.

Plant Chronobiology - Flame Violet

Open during the day

Plant Chronobiology - Flame Violet Plant Chronobiology - Flame Violet

Close at night

And last week, from my bonsai instructor, I have finally got a clue! Once I told him about my Episcia, he said, “There is nothing to worry about. Your plant, like you do, needs some sleep too.”

That makes sense. This is just how the world works – we work during the day and sleep at night (or reverse), and so do many other organisms.

And the more research I have done on this topic, the more I find it interesting. It appears that the daily opening and closing of the leaves may not simply be a response to the sun, but the circadian rhythms in plants. And what I have observed is the sleep movements of my Episcia.

Throughout history, many botanists had studied extensively on this phenomenon of plants. Charles Darwin published an entire book on the Movement of Plants, suggesting that the plant itself generates the daily rhythms. And by using this behavior of plants, Carolus Linnaeus invented the flower clock. While it is not easy to make a functioning flower clock, people have done it.  Here is the Solar Clock built in Truman State University.

If you are interested in learning more about the sleep movements of plants, here is a good article written by a chronobiology specialist – Clock Classics: It all started with the plants.

9 comments to Our Plants Need to Sleep Too!

  • Sandy, just like us, plants do sleep in various forms. Ulam Raja in our garden exhibits similar pattern, the younger leaves at the top, fold up like a crown, slowly after 7pm…. Interestingly some plants has leaves drooping, looking very tired as a signal of a very sound sleep.

    ~ bangchik

  • Sandy Sandy

    Yes Bangchik, the more I learn about plants, the more I find them just like us 🙂

  • Jen

    Thanks for visiting, nice to hear from you.

    I have a cutting from a friend, of a flame violet. It is in a little 2 inch pot, and bad gardener that I am, I have been neglecting it.

    But it seems to be doing fine, just a little stretched tall. Well aren’t we all?

    Can’t wait for it to bloom.


  • a very interesting concept! when I was growing seedlings I used the artificial lights, sometimes leaving them on for 2 days at a time! They didn’t seem to suffer though;-) When I realized it, I would leave the light off for a while to give them a rest. I know if I’d left it on for too much longer, they wouldn’t have done well. They are living things and need air, water, and sleep;-) Yawn:-) I think I’ll go take a nap now!

    • Sandy Sandy

      Jan – Same here. After I’ve learned more about the sleeping cycle of plants, I turn off the light at night to give them some time to rest too.
      Autumnbelle – Thank you. The more I learn about plants, the more I find we (all living things) are alike.

  • Sandy, you have a very interesting and informative article here especially on circadian rhythms in plants. Very good post. Cheers!

  • Rosemary

    I would like to purchase the flame violet. I had one years ago and left it in the care of a fool. I have looked all over my area to no avail. PLEASE help me!!!

    • Sandy Sandy

      Rosemary – Instead of buying flame violet in a shop, maybe you can propagate one by stolon cutting. Do you have a friend who has a pot of flame violet? Or neighbor? 😉

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