The 10 best houseplants to help you sleep? More like the zero best plants!
There is so much misinformation out there about gardening that I’m at a loss for words! Do a web search on “sleep-inducing houseplants” and you’ll find articles galore, especially in lifestyle magazines.
Supposed Virtues of Houseplants
The supposed virtues of indoor plants for sleep? Air purification, relief of joint pain and nausea, reduction of blood pressure and heart rate, increased humidity, decreased anxiety. It’s a miracle cure! One article even suggests that a cactus placed near electronic devices protects us from electromagnetic waves (I won’t even waste time denying this nonsense, but others have!)
The truth is that, apart from the happiness and actual well-being they bring us, houseplants will not replace medication or natural products and are not particularly sleep-inducing.
Myths to Debunk
For starters, we now know that houseplants are not experts in air purification. While they can clean the air of volatile organic compounds (VOCs) in a small, controlled environment, it would take hundreds of plants per room to have a measurable effect. It’s much easier to open a window to “change the air” if you don’t already have a purifier or air exchanger.
Since the soil in which our houseplants grow contains water, there is a slight, very localized increase in humidity when watering. If there really was an increase, the effect could be beneficial, especially in winter when the air in our homes tends to be dry. But the positive effect of watering on humidity is not only negligible, but evaporation will soon eliminate this small benefit. In fact, it’s better to use a humidifier in winter because our plants suffer from dry air rather than eliminate it.
Bringing the Outside In?
Another major problem with studies that try to demonstrate a positive effect on sleep is that the plants used are outdoor plants! One plant often cited in articles on the subject is lavender, whose scent is said to improve sleep quality. But, to my knowledge, it’s almost impossible to grow it indoors. For starters, it’s a plant that needs a lot of light even outdoors, so it’s unlikely to get enough indoors. Also, lavender requires cool temperatures at night, especially in the fall, when it’s suggested to lower the temperature to 10°C. In fact, you are trying to simulate outdoor conditions, a waste of time, in my opinion. It would be more efficient to buy dried lavender or essential oils.
Other plants studied for their effect on sleep? Cilantro, strawberry, ylang-ylang, basil, all plants that will be extremely difficult to grow indoors. Unless you want powerful grow lights in your bedroom, turned on at least 12 hours a day, ditch the project and choose more typical houseplants as roommates.
Danger of Plants in the Bedroom?
During the day, plants absorb carbon dioxide (CO2) and release oxygen (O2). At night, since they have no light to transform into glucose, they release CO2. The process is, in a way, reversed. An urban legend says that we should not keep plants in our bedrooms because we risk CO2 poisoning. In reality, plants don’t release enough carbon dioxide to have a harmful effect on humans, who themselves produce much more. It’s therefore perfectly safe to have indoor plants on our bedside tables.
We already know that the presence of plants in our environment reduces stress levels, relieves people suffering from depression and anxiety, improves our attention span, helps us heal faster, and increases productivity and creativity in the workplace.
One study shows that a 15-minute interaction with plants before bedtime in an isolated environment reduces stress, sleep latency, and the number of microawakenings. However, this study was conducted in an enclosed environment similar to astronauts in a spacecraft, so we cannot extrapolate this information to our situation. Another study shows that the mere sight of a bamboo plant induces relaxation!
So what’s the truth about houseplants and sleep? Does the well-being that houseplants bring help us catch some Zs? We can’t say for sure, but it’s a possibility. More studies need to be done on the subject to understand the how and why. In the meantime, I already have several plants in my bedroom. They are beautiful and I enjoy seeing and caring for them. I sleep well, on my own, whether it is thanks to my plants or not! As for you, dear readers, if you really insist on having a plant helps you sleep, you may have to smoke it…