Are cut flowers really bad for hospital rooms?

There are long-standing urban legends and old wives' tales regarding flowers and the sick.
There are long-standing urban legends and old wives' tales regarding flowers and the sick.

In the "get well soon" world, flowers are the go-to gift. They brighten up a dull room, bring some nature into the picture and are just plain good at cheering people up -- which makes it all the more strange that lots of people think flowers should never be placed in a hospital room. Some hospitals even have rules to that effect.

The belief is fairly entrenched, and it goes back a good ways. The urban-legend experts at Snopes have traced it back to 1923 in print form, and it most likely spread via word of mouth long before that [source: Snopes]. The myth goes like this: Flowers are bad for hospital rooms because they suck oxygen out of the air. And sick people need their oxygen.


This oxygen-sucking myth is just one of many longstanding beliefs regarding flowers and ill health. An old wives' tale common in England states that if you put red and white flowers in a single vase in a hospital room, a person in the surrounding ward will pass away [source: Snopes]. Another common legend goes that patients should always leave flower arrangements behind in the hospital room when they're discharged; if they bring the flowers home, they'll end up right back in the hospital [source: Snopes].

The difference between these myths and the oxygen-depletion belief is that the latter seems to have a scientific explanation. But is it really any different?

In this article, we'll look at the belief that flowers are bad for hospital rooms. We'll find out whether the science is sound, and look at other evidence of flowers' effects on sick people.

So, what's the truth about cut-flower arrangements and air composition?


Deadly Blooms?

Flowers are more likely to improve your mood than make you sicker.
Flowers are more likely to improve your mood than make you sicker.
Gerry Cranham/Fox Photos/Getty Images

On its face, the oxygen-depletion myth appears to have some backing. 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.

So, flowers are bad, right?


In fact, flowers add far more oxygen to a hospital room than they use. In daytime, plants emit 10 times more oxygen than they use up at night, so a hospital room with flowers in it will actually end up more oxygenated than one without [source: Snopes]. And a study published in the journal International Archives of Occupational and Environmental Health in 1977 showed that even at night, plants only altered oxygen and CO2 levels in hospital wards by about 1.5 percent -- a negligible amount, in terms of air composition [source: Gale].

It's especially negligible when you consider that a human being, such as the sick person lying in the bed in the hospital room, uses up about 2.5 cubic feet (71 liters) of oxygen in an hour, while a pound of foliage sucks up about 0.026 gallons (0.1 liters) in that same time period. It would make far more sense to ban oxygen-sucking visitors than to ban flowers.

So why would a hospital ban flowers from intensive care units? Some people think the myth is simply so pervasive, hospitals have incorporated it in their policies. But more likely, it has to do with a potentially real health hazard associated with cut flowers: bacteria. Studies have shown that the water in a vase of cut flowers can carry harmful bacteria -- the kind of stuff that can cause infectious disease [source: Kates].

However, according to a 2005 study published in the British Journal of Infection Control, this bacterial source has never actually led to a case of patient illness [source: Gould].

And at least one study has shown that having flowers in a hospital room makes patients feel better. A 2008 study in the journal of the American Society for Horticultural Science revealed that patients in hospital rooms containing flowers or potted plants used less pain medication and had lower blood pressure than patients in rooms without them [source: Park].

If you weigh, then, the apparently negligible chance that floral bacteria could make a patient ill with the very real possibility that flowers make people feel better (and actually increase the oxygen supply), the decision -- to send or not to send -- seems pretty cut and dried.

Flowers are as good for sick people as they are for everyone else.

For more information on flower mythology and old wives' tales, look over the links on the next page.


Lots More Information

Related HowStuffWorks Articles


  • Flowers May Help After Surgery. KIRO TV. Dec. 31, 2008.
  • "Flower Power." Snopes.
  • Gale, Rena, Rivka Redner-Carmi, and Joseph Gale. "Impact of the respiration of ornamental flowers on the composition of the atmosphere in hospital wards." International Archives of Occupational and Environmental Health. Volume 40, Number 4 (December 1977). 255-259. SpringerLink. Dec. 10, 2004.
  • Gould D, et al. "The evidence base and infection risks from flowers in the clinical setting." British Journal of Infection Control, Vol. 6, No. 3, 18-20 (2005). SagePub.
  • Hospital Flowers. The AFU and Urban Legend Archive.
  • Kates SG, McGinley KJ, Larson EL, Leyden JJ. "Indigenous multiresistant bacteria from flowers in hospital and nonhospital environments." Am J Infect Control. 1991 Jun;19(3):156-61.
  • Park, Seong-Hyun, Richard H. Mattson. "Effects of Flowering and Foliage Plants in Hospital Rooms on Patients Recovering from Abdominal Surgery." HortTechnology, Vol. 18, No. 4. (Oct. 1, 2008), pp. 563-568. CiteULike.