Flowers in Hospitals: Do Flowers and Plants Suck Oxygen From Sick Rooms?

No, they produce it.

OK, let’s assume you missed school the day they taught photosynthesis. (Where were you, anyway?) Let’s get you caught up before you think twice about bringing flowers to a beloved hospital patient.

Photosynthesis is a process that takes place using chlorophyll (the green in green plants) and turns carbon dioxide and water in the presence of light into sugar and oxygen. Yes, the very same oxygen you breathe with every breath. You do know you breathe oxygen, don’t you? Ahem.

Without photosynthesis, life as we know it on this planet would not be possible, as all the oxygen would be used up and converted to carbon dioxide by now. In fact, Earth originally had very little oxygen – it was the advent of algae and green plants that changed the situation. Suffice it to say, you’d be gasping for air right now if not for all the friendly green plants producing oxygen for you to breathe.

They say that the first photosynthetic organism appeared 3.5 billion years ago. They had plenty of carbon dioxide around to support their lifestyles, so oxygen production steadily increased along with the plant population. But copious amounts of oxygen weren’t created until 2.4 billion years ago, when the cyanobacteria became big players. After that, plants started evolving into more complex organisms, until eventually we had the beautiful flowers that grace today’s patient sick rooms.

In photosynthesis, the plant chloroplasts contain surfaces where electrons are transferred from water to carbon dioxide, building up organic molecutes along the way. Remember the Calvin cycle from high school? Don’t remember high school? Well, never mind, just trust us that the chemistry works to support growth of the plant as well as energy production.

The first printing of this urban myth dates back to 1923, but before that the myth circulated by word of mouth. We are unsure of its origins, except in the depths of someone’s ignorance of biochemistry. Now, to be fair, at night (when the sun doesn’t shine), plants do take up oxygen and give off carbon dioxide, just like you do. However, next morning, our hearty little specimen will resume providing ten times the oxygen it used up the previous night. Thus, plants make hospital rooms healthier by making more breathable air. The plant kingdom would like you to remember this fact the next time someone approaches you with an accusing look as you bring flowers into the hospital. It’s OK. Really!