You may have heard that having plants in your bedroom (at least at night) was dangerous. Why? Because plants compete for oxygen while you sleep. This explanation is sometimes followed with some worrying eventuality such as ‘causing you to suffocate’. So today I want to clarify some things and put to bed whether this is Truth or Myth.
The simple answer is that it’s Myth! But let’s look at why:
Photosynthesis and Respiration
Photosynthesis is a chemical reaction that happens during the day in the chloroplasts of plant cells. Carbon dioxide and water react together in the presence of light and chlorophyll to make glucose for use by the plant, and oxygen as a waste product.
To unlock the energy produced in photosynthesis, green plants need to respire, just as animals do. Respiration takes place in the plant’s cells, using oxygen to produce energy and giving off carbon dioxide as a waste product.
So in terms of the gas taken in and the gas given out, respiration is the opposite of photosynthesis. Luckily, plants use up more carbon dioxide in photosynthesis than they produce in respiration, and produce more oxygen while photosynthesising than they use up while respiring.
Day vs Night
Plants are continuously engaging in cellular respiration, but can only photosynthesize during the day (they need light!).
During the day when the plant is both respiring and photosynthesising there is a two-way traffic of oxygen and carbon dioxide both into and out of the plant. However, the amount of oxygen plants release as part of photosynthesis makes the amount of oxygen they consume for respiration seem so small as to be almost meaningless.
During the night when the plant is respiring but not photosynthesising, oxygen is being taken in but not given out – and carbon dioxide is being given out but not taken in. In other words: at night, when photosynthesis can’t happen, plants continue to consume oxygen but they don’t release any back into the room. “So plants really do compete with humans for oxygen then?” Well, not really. The amount of oxygen plants use at night is still way too minimal to be able to take our share of available oxygen.
While we’re not going to suffocate from having plants in our bedrooms, having an abundance of oxygen can have a calming effect, reducing anxiety and insomnia. Taking this into consideration there is one more thing we can look at in relation to plants; a type of plant that can still add something new to the picture for any with left over concerns.
Some plants can actually uptake carbon dioxide during the night. This is because of their ability to perform a type of photosynthesis called Crassulacean Acid Metabolism (CAM). These plants have adapted to cope with arid climates, the stomata in the leaves remain shut during the day to reduce evapotranspiration, but open at night to collect carbon dioxide, which is then stored as acid malate. When day arrives, the malate is transported to chloroplasts where it is converted back to CO2 to be used during photosynthesis. So keeping CAM plants in your bedroom can be more beneficial to your sleep than those who use C3 or C4 photosynthesis.
Due to their climatic adaptations, it’s not surprising that they include the following:
I won’t go into listing ever single cacti, but it’s safe to say that cacti generally use CAM photosynthesis, so pick your favorite and enjoy.
Many succulents are CAM utilisers, such as: Aeonium, Echeveria, Kalanchoe, and Sedum of the family Crassulaceae. As well as Agave (Deserti Engelm), the Jade plant (money tree), the Snake Plant (mother in law’s tongue), Kalanchoe daigremontiana (the ‘Maternity plant’, or ‘Mother of Thousands’), the vining Wax plant, and probably the most useful of which is Aloe.
Pineapples for food and oxygen, what more could you want? How about a Spanish moss for some delicate beauty?
Sporophytes of some epiphytic species in the fern genus Pyrrosia exhibit CAM.. So if you’re a fern lover, you can just about get away with using this as an excuse to keep them in your bedroom.
I’d also like to give a few examples of plants that produce a lot of oxygen during the day:
This plant happens to convert a lot of CO2 (carbon dioxide) to O2 (oxygen) during the daytime. It also helps remove xylene and toluene from the air. Having four shoulder-high plants per person in your household provides enough oxygen to survive on during daylight hours! In order to function well they do need to have dust and grime wiped off of their leaves once a week, or as often as daily if you live in a city with very bad air quality.
You may have noticed it earlier in the succulent CAM plants section, but this one is a great oxygen producer during the day too!
If you grow your own sprouts for food (especially sweet pea sprouts, buckwheat sprouts and sunflower sprouts) you will have a fantastic mini greenhouse effect in your living space. You also get supplemental oxygen orally by eating raw, living greens!
Don’t underestimate the power of plants; it is said that 6 to 8 waist-high Snake plants in combination with 4 shoulder-high Areca Palms (that convert a lot of carbon dioxide to oxygen during the daytime) would allow a person to live in a completely air sealed room!