When you settle in for a night of restful sleep, you don’t want anything in your bedroom that could be potentially harmful. You never thought of your indoor plants that way until you heard a fellow gardener mention that plants release carbon dioxide at night. Is sleeping with a few houseplants in your bedroom at night dangerous for your health?
Are indoor plants harmful at night? No. Although many houseplant species tend to release carbon dioxide at night rather than oxygen, the quantities of carbon dioxide are often not significant enough to cause breathing difficulties or to worsen sleep apnea.
Ahead, I’ll talk more about why having houseplants in your bedroom at night isn’t a bad thing so you can make a safe decision for your own household. I’ll even share a few plant species that release oxygen 24/7 if you want to grow those instead.
Let’s get started.
Plant Behavior 101: Photosynthesis and Respiration
To understand why some people are concerned about keeping plants in the bedroom at night, I first want to explain how plants behave at night versus during the day.
All plant species, indoors and outdoors, undergo photosynthesis. Plants aren’t the only ones, by the way, as bacteria and algae can photosynthesize as well.
Through photosynthesis, a houseplant will take in light–be that artificial light or natural sunlight–to synthesize water and carbon dioxide. The result is chemical energy the plant can use for other activities such as growth.
When plants photosynthesize, they take in carbon dioxide and release oxygen. This is inherently beneficial to anyone and everyone around the plant, from animals to us people. That’s because we need oxygen to breathe and survive.
Since light is a main requirement of photosynthesis, plants will only photosynthesize during the day. At night, when light is in short supply, plants begin another process known as respiration.
This is a second means of generating energy for the plant. During respiration, the plant takes the oxygen and the sugars it produced from photosynthesis to make energy to continue growing. Oxygen must be present for the cell’s mitochondria to undergo aerobic respiration.
So while photosynthesizing requires a plant to take in carbon dioxide and release oxygen, during respiration, the opposite happens. Now the plant needs the oxygen to respirate, so it takes that in and releases carbon dioxide instead.
What Are the Perceived Risks of Having Indoor Plants in the Bedroom?
Okay, so what exactly is carbon dioxide anyway?
According to a February 2020 report from Climate.gov, in 2018, the world had 407.4 parts per million (PPM) of carbon dioxide in the air. It’s already out there, and you are breathing it in. However, since oxygen is also in the air, you don’t often feel the potentially harmful effects of carbon dioxide.
The Canadian Centre for Occupational Health and Safety or CCOHS notes that too much carbon dioxide in the air can impact your respiratory ability and even lead to central nervous system depression. Enough carbon dioxide can force the oxygen out of the air, triggering symptoms such as fatigue, emotional changes, clumsiness, increased heart rate, and fast breathing.
If oxygen quantities continue to lessen from there while more carbon dioxide is in the air, your symptoms will worsen. These symptoms may include convulsions, collapse, vomiting, coma, and even death in some cases. The more physical activity you do when the air is so poorly oxygenated, the faster the symptoms can take hold.
It’s also important to watch your carbon dioxide levels in the bedroom if you have a condition like sleep apnea. That’s because your blood carbon dioxide increases with this condition. Thus, more carbon dioxide in the air, especially in the bedroom, could possibly lead to the above life-threatening symptoms for those with sleep apnea.
Are Indoor Plants Harmful at Night?
That brings us back to the main question: is it a bad idea to keep houseplants in your bedroom, especially at night?
It can be, but for the most part, no, it isn’t.
It’s true that houseplants respirate at night, releasing carbon dioxide, but not all houseplant species do this. In the next section, I’ll share some unique plants that keep on releasing oxygen when the sun goes down.
Also, even if your houseplant does happen to respirate, it’s likely not sending enough carbon dioxide into the air to cause any ill effects. Remember, you breathe in carbon dioxide all the time anyway. If there’s enough oxygen in the air, the carbon dioxide won’t impact your health.
Some resources out there like to paint a picture of houseplants as inadvertent killers, but this is just an overblown myth. Your plants aren’t trying to kill you.
That said, it can be a bad idea to have houseplants in the bedroom in some instances.
If you have a particularly small bedroom for example and you close all the doors and windows tight at night, that could possibly be a risky situation. The same is true if you have a dozen plants in your bedroom.
If you have sleep apnea, you also might want to keep the plants out, just to be safe.
So how many houseplants is the right number here? If your bedroom is 13 feet by 16 feet, then no more than 10 plants. That’s still plenty generous.
Remember also that houseplants do more than just add carbon dioxide into the air at night. They can also boost the air quality, not only in your bedroom, but elsewhere in your home and even your office.
Indoor plants will lessen allergens in the air as well as benzene and formaldehyde.
A type of chemical compound, benzene is flammable with a sweet smell and a sometimes-yellow color. High levels of benzene can cause unconsciousness, confusion, tremors, headaches, fast and irregular heartbeat, dizziness, drowsiness, and sometimes death.
Formaldehyde is another chemical compound that floats in the air as a gas with no color. Ingesting more than 0.1 PPM of formaldehyde can cause irritated skin, nausea, wheezing, coughing, and a burning feeling in your throat, nose, and eyes. It may also be attributed to cancer deaths per this 2009 article in The New York Times.
10 Indoor Plants That Release Oxygen at Night
Now you know that a few houseplants in your bedroom are nothing to fear at night. Still, you’d rather tread on the cautious side, which is why you’d like to own plants that only release oxygen around the clock.
You have plenty of indoor plant species to choose from, including the ones on this list.
The Hedera helix–also referred to as the European ivy, common ivy, or English ivy–will drape over the walls of your bedroom for more drama.
This Araliaceae family member also keeps the air in your bedroom free of allergens so you sleep more soundly and wake up less stuffy and congested.
As a warning, you do want to keep pets out of the bedroom if you’re growing English ivy. It’s toxic to both cats and dogs when consumed due to the triterpenoid saponin within.
A classic indoor plant for a reason, the Chlorophytum comosum or spider plant doesn’t stop making oxygen even when the sun goes down.
This plant with its long, spindly leaves ala the insect it’s named after is also awesome at purifying the air. You’ll sleep better knowing the spider plant in your bedroom is helping to by removing the carbon monoxide, formaldehyde, and benzene in the air.
Pothos (Epipremnum sp.) is one of my favorite indoor plants to have in my bedroom. Not just because it also produces oxygen but because it grows so well in the low light corners of my room where other plants wouldn’t last a week.
The beautiful Transvaal daisy, also known as the Gerbera daisy (since its scientific name is the Gerbera L.) is an Asteraceae family member that’s great to add to your indoor garden for several reasons.
For one, the appealing flowers in hues like yellow, white, orange, red, and pink will brighten up any bedroom.
Also, the Gerbera daisy doesn’t stop releasing oxygen even if the sun isn’t up. You can give the daisy medium light and the flowers will still bloom, making this a great houseplant to care for.
Another pretty yet beneficial houseplant for releasing oxygen is the peace lily or Spathiphyllum.
These Araceae tropical family members were part of that classic NASA study on plants and air quality. The peace lily also made our list of the best bedroom houseplants.
That’s due to the peace lily’s capability of clearing away xylene, carbon monoxide, toluene, formaldehyde, benzene, and other volatile organic compounds. Oh, and this faux flower will also add more oxygen to the air as you sleep.
As a succulent, the aloe vera doesn’t need much water. It does have lots of oxygen to give though, which it will do around the clock. This evergreen perennial will look great in your bedroom, and it’ll make it easier to breathe in there to boot.
Here’s a species of houseplant I have yet to introduce you to. The Tulsi is also referred to as the holy basil.
Scientifically known as the Ocimum tenuiflorum, the Tulsi is a Lamiaceae family member that comes from the Indian subcontinent. It’s since spread throughout the tropics of Southeast Asia.
Its leaves not only smell great, but the odor of the Tulsi is said to be able to lessen anxiety and jangled nerves. You could even eat the leaves, which supposedly help with memory and can alleviate cold symptoms and fevers.
The Tulsi also produces oxygen continuously, so why not grow some?
Also known as a “Ficus” (Ficus benjamina). The weeping fig or ficus is different from the other indoor plants on this list that produce oxygen because it’s technically a tree.
Albeit a smaller tree especially when grown indoors, I find having a weeping fig growing indoors to add oxygen and variety to my indoor plant collection is a nice touch. I also place the taller indoor plants, such as the weeping fig, near some of the smaller plants to create a natural canopy of shade for my plants that thrive in more shaded environments.
The Dracaena trifasciata also makes the list for houseplants to keep in your bedroom overnight. An Asparagaceae family member, the snake plant will rid your bedroom of formaldehyde when you close the door to sleep. It also keeps up quantities of oxygen.
The last houseplant I recommend for more peaceful nights is the Areca palm or Dypsis lutescens.
Also referred to as the butterfly palm, yellow palm, or the golden cane palm, the appealing yellow-green color of this houseplant species isn’t all that’s great about it.
The Areca palm can also free the air in your bedroom of benzene and formaldehyde as well as maintain oxygen levels at night.
Plants photosynthesize by day, taking in carbon dioxide and releasing oxygen. At night, some plant species respirate, adding carbon dioxide back to the air.
If you don’t put too many plants in your bedroom, then the quantities of carbon dioxide from your houseplants shouldn’t be enough to cause harm.
You can also add to your indoor garden any of a slew of houseplants that make oxygen even at night. These include the Areca palm, spider plant, Tulsi, peace lily, aloe vera, and more.
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