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Because we live in southern Canada, in the late fall, my mother likes to take as much of her garden indoors as she can fit, for the winter.

She usually brings in her potted palms, a few flowers, at least one pot of each of her dozen or so types of herbs, and before moving to a smaller place, she would also bring in as many pots of tomatoes as she could fit.

She arranges them all next to the window, waters them once a week, and plugs one or two lights into a timer that is programmed to turn on just when it’s getting dark, and off just when it’s getting light.

This has always made me wonder if plants can have too much light. I tried Googling it, but all the discussions I found were about burning from too much sun (ie, too much heat/UV/etc.) That is not the issue here since the light(s) are just 13W CFLs. My issue is more with the idea that as far as the plants are concerned, it is always day and night never comes.

When I was studying psychology in University, one thing I found very interesting was the study of sleep and circadian rhythms. I’ll never forget reading about various experiments on sleep deprivation and their effects. Moreover, in my biology courses, we learned how (most) plants have a two-phase cycle: an anaerobic one (i.e. “breathing” CO₂) during the day, and an aerobic one (“breathing” O₂) at night. These make wonder what effects having a constant source of light would have on the plants. After all; all day and no sleep make humans something something… what about plants?

Because we live in southern Canada, in the late fall, my mother likes to take as much of her garden indoors as she can fit, for the winter.

She usually brings in her potted palms, a few flowers, at least one pot of each of her dozen or so types of herbs, and before moving to a smaller place, she would also bring in as many pots of tomatoes as she could fit.

She arranges them all next to the window, waters them once a week, and plugs one or two lights into a timer that is programmed to turn on just when it’s getting dark, and off just when it’s getting light.

This has always made me wonder if plants can have too much light. I tried Googling it, but all the discussions I found were about burning from too much sun (ie, too much heat/UV/etc.) That is not the issue here since the light(s) are just 13W CFLs. My issue is more with the idea that as far as the plants are concerned, it is always day and night never comes.

When I was studying psychology at University, one thing I found very interesting was the study of sleep and circadian rhythms. I’ll never forget reading about various experiments on sleep deprivation and its effects. Moreover, in my biology courses, we learned how (most) plants have a two-phase cycle: an anaerobic one (i.e. “breathing” CO₂) during the day, and an aerobic one (“breathing” O₂) at night. These make me wonder what effects having a constant source of light would have on the plants. After all; all day and no sleep make humans something something… what about plants?