Yes we say it they rest at night so don't disturb them but may be at night they exhale carbon dioxide so its saying that we should not go nearby them. :)
Yes thats true plants exhale carbon dioxide at night as the process of photosynthesis stops during night time.
there is a common theory behind this that they take oxygen and release carbon dioxide into the air.............
yes, plants sleep at night. actually people say not to touch plants after 6. as they sleep from evening. if we touch at that time they will curse us. At night time we should not sleep under trees or plants because at night time plants also release carbondioxde. like human.
