A common myth states that, at night, plants compete with people for oxygen! All plants and animals on earth engage in a process called respiration. Respiration combines oxygen and the food created during photosynthesis to produce usable energy. One of the byproducts of respiration is carbon dioxide.
Do plants breathe in oxygen at night?
As photosynthesis requires sunlight, this process only happens during the day. We often like to think of this as plants `breathing in carbon dioxide and `breathing out oxygen. Fortunately for all of us oxygen breathers, plants produce approximately ten times more oxygen during the day that what they consume at night.
Do flowers absorb oxygen?
It's true that while plants typically absorb carbon dioxide and emit oxygen, that process changes at night. At night, plants absorb more oxygen than they produce, and they emit carbon dioxide. In fact, flowers add far more oxygen to a hospital room than they use.