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This is something is we hear all the time as a benefit of keeping houseplants… but is there any truth to it?..
Do house plants clean the air?
Clean the air of what?
Misunderstanding, anger, tension, anxiety, worry, confusion, inattention … all of these things might be somewhat cleared by the presence of lots of houseplants, because studies have shown many times the psychological and emotional benefits of plants in the environment.
But you probably mean “air pollutants,” right?
There is research that has shown that plants (or more likely, the soil they’re planted in,) absorb a number of air pollutants.
That same research, however, also shows that one plant absorbs very little of those pollutants, even in a closed laboratory.
In a real life home, with outside air coming in all the time, you would need so many plants to clear the air enough to even measure, you would barely have room to move around.
Sorry to tell you this, but indoor potted plants don’t clean the air in a home, although they are pleasant to have around: Massive Review Confirms House Plants Aren’t Actually ‘Purifying’ The Air in Your Home
It’s not just me saying something crazy. There’s been plenty of research that shows this. But people everywhere keep saying “plants clean air.”
Research behind “do house plants clean the air?”
In the 1970’s, Dr. Bill Wolverton began working with NASA to research using plants as air purifiers in closed environments. These experiments led to the famous “Wolverton Clean Air Studies,” (Plants Clean Air and Water for Indoor Environments).
These in turn led to a number of other studies of plants as air quality improvers, which has led us to – in 2020- about a billion articles and discussions online about “plants that clean the air.”
In the studies, typically a number of plant species would be used, from 3 or 4 to maybe 10, 12, maybe even more (can’t say for sure, haven’t read all the studies.)
While some plants would show through the readings that they were better at removing some toxins than others, all the plants used showed positive readings.
So someone would report on these studies, listing the names of the plant varieties used in them, and these would become “good plants for air quality”– but until someone does an exhaustive study on all indoor plant varieties, you can’t really say that only the plants already used are the only ones that can do the job.
So I make the speculation – all plants have some value in improving indoor air quality.
There are many problems with the plants for clean air studies, chief among them being that the results are not reliably duplicatable. Critical Review: How Well Do House Plants Perform as Indoor Air Cleaners? .
One big factor is that the environment inside closed experimental chambers bears little resemblance to real life environments within homes and offices.
Another is that there are so many variables in play – specific to plants, these include things such as the size, condition and number of plants relative to size of space; the health of the plants, meaning they must have the correct amount of light, moisture, fertilizer, pest and pathogen protection; the soil needs to have the correct balance of pH, minerals, organic and inorganic elements, drainage; and the list goes on.
One big question is how many plants does one actually need to “clean the air” in your home?
One analysis extrapolated from different laboratory “air chamber” studies that one would need 680 plants in a 1500 sq ft house to achieve the same air cleaning results as those achieved in the laboratory!
One thing is clear – a couple of plants here and there in your home isn’t going to help.
While it’s been shown that there is a correlation between the presence of live potted plants and the reduction of various toxins in the air, the effectiveness of anything but a very large number of healthy plants, living in a closed and controlled environment, is questionable.
So lets look at the flip side of having an organic compound living in our home…
Can plants negatively affect indoor air quality?
Yes. Plants can release pollens and some of their own volatile organic compounds.
Flora and fauna living on the plant and in the potting soil can have their own emissions. Pesticides and fertilizers used to care for the plants also have their contribution.
If you have concerns about the air quality of your indoor environment, you’re far better off to invest in conventional air filtration/ purification systems than in a few plants.
I’m not suggesting that you shouldn’t have plants – it’s my business, after all.
I am saying, however, that the real value in houseplants lies in directions other than “air cleaning” – they are a wonderful interior design tool, they are beautiful, they make people feel good, they reduce anxiety, they have a positive effect on productivity and creativity, they are an inexpensive and fascinating hobby.
Just my personal opinion, “air cleaning” is way down on the list of reasons why you should get a few plants.
Clean Air Quick Picks
OK, so I’ll also answer your question about “good plants.” If you want to get a few plants, for whatever reason, you’ll get the most satisfaction from those that are easiest for a beginner to grow.
My top 7 favorite easy to grow plants are:
- snake plant
- peace lily
- parlor palm
- spider plant
- corn plant
- chinese evergreen
They’re all tolerant of many light conditions, some over- or under-watering, and your humidity and temperatures whatever they are.
Do a little reading about them to find out more about their care – plants are very easy, taking only a minute each every week or two, but there are a few things to know.