Everybody knows that plants need light for photosynthesis, to grow and remain healthy; but do they require (or benefit from) sleep/darkness; or can they be bathed in light 24/7?

I'm not talking about a need to shelter from the weather, UV & IR radiation, etc. Just the visible light spectrum.

For instance: I have some moss growing indoors, under a bright LED light. Is it okay to leave it on constantly, to maximize growth; or should I rotate 12 hour shifts?

  • There are many other variables at work as well but I will always give my plants dark periods. Not to be a 'nice' steward but biologically and botanically life needs a period of rest. Lots goes on without the stress of photosynthesis during the dark. We were all evolved with light and dark periods. I've heard some plants are able to shut down even with light. Want to know other ways to promote growth and vigor? Ask another question TJT!
    – stormy
    May 25, 2017 at 20:42
  • That is my thinking as well, but is there evidence of this? Maybe we are anthropomorphising.
    – voices
    May 25, 2017 at 21:36
  • Anthropomorphizing is a very big deal we all have to keep checking ourselves from using. In this case we are talking about plants and animals and I've read some great stuff on this...in my own library that is now in storage!! If I can come up with some good evidence I will most certainly send that to you! Glad you are a skeptic!
    – stormy
    May 25, 2017 at 22:40
  • I am OCD when there are questions I do not know the answer to in detail. Check out this site. popsci.com/blog-network/our-modern-plagues/do-plants-sleep
    – stormy
    May 26, 2017 at 18:30
  • This was also included with the last article...plants are far smarter than we give them credit. night/day and circadian cycles are more about their CLOCK they use to decipher their environment. Using this clock they are able to time when to use their own 'pesticides' and other defense systems with certain insects that can do major damage. A very wow! paradigm about plants. I know plants are aliens we humans know very little about and this is just another humbling...fact? plantcell.org/content/18/4/792.full
    – stormy
    May 26, 2017 at 19:08


Browse other questions tagged or ask your own question.