What Happens to Plants at Night in the Dark? The biggest change in plant metabolism in the dark is that they stop photosynthesis, because that is a biochemical process that needs light to happen. This is how plants make their food, which happens in the leaves as long as the light is shining.Click to see full answer. Consequently, what do plants do in the dark?Plants usually produce oxygen during the day due to photosynthetic reactions and use oxygen at night due to respiration. Owing to their internal circadian rhythms, while it’s dark, plants anticipate the coming of dawn and prepare for it on a cellular level before their chloroplasts are stimulated by light.Also Know, what will happen to a plant left in the dark? While temporarily placing a house plant in a dark room may not cause it any immediate harm, all plants eventually die without sufficient light. Light is the energy source that allows plants to convert carbon dioxide and water into complex carbohydrates such as glucose. Likewise, people ask, do plants grow in the dark? Plant Growth in Darkness Plants grow fast in the dark, and do so because they operate on circadian cycles. In simplistic terms, it makes sense that plants would grow at night since daylight activity consists of absorbing light for photosynthesis.How Long Can plants survive in the dark?So while there are plants (like full-sun annual flowers, for example)that require maximum light every day, and might die within a week if placed in a dark room, there are others (many interior foliage plants) that can live for years photosynthesizing on nothing but the ambient light of indoor lamps.