The leaves of 홍자귀 close up at night; is there a problem with it?
This is a situation where someone growing 홍자귀 sees its leaves closing up in the evening or on cloudy days and worries whether something has gone wrong with the plant.
홍자귀 performs sleep movements by folding its leaves on its own when it gets dark or when light decreases, so it is a natural phenomenon rather than wilting.
The leaves of 홍자귀, which spread out in a feather shape during the day, neatly close inward at night or on cloudy days[1][2]. This is a normal sleep movement of the plant, opening and closing its leaves in response to the amount of ambient light[3]. Sleep movement is a phenomenon where petioles move according to changes in light and temperature, reducing moisture loss during dark hours.
홍자귀 also displays a distinct contrast in colors as it grows. New shoots, meaning newly emerging young leaves, initially come up with a reddish tint, but gradually turn into a fresh green as they grow[4][5]. The depth of the reddish hue held by the new shoots also varies depending on the light the plant receives and the surrounding environment[6].
The optimal illuminance standard or specific care temperatures that induce sleep movement have not yet been confirmed in official materials.