Best Air Purifying Indoor Plants (c/o NASA scientists)

This article examines air purifying plants and lists some of the best indoor plants for clean air.

What is cool is that a lot of this research stems from NASA and scientists that worked at NASA.


This article has some affiliate links. If you click a link and buy a product, I’ll receive a small commission at no extra cost to you. The money helps to support the website and my family. 🙂 For more information see my Disclosure page.



What does indoor air pollution have to do with new houses?

Potential Problem with Airtight Houses

New energy-efficient houses minimize drafts – the transfer of air from inside the house to outside and vice versa. Gaps between the doors and windows are caulked and sealed. Walls are thick and wrapped in vapor barriers and other house wrap materials.

The house doesn’t naturally “breath” on its own. It is all closed up.

This helps make the house energy-efficient because you’re not letting heated or air-conditioned air escape to the outside, but it also means any indoor air contaminants will stay inside for longer.

They will no longer naturally drift outside like they do in old “holey” houses.


New homes can be close to air-tight



Whats NASA got to do with it?

A space shuttle is the ultimate experiment in controlling air quality.

And NASA was very interested in determining if plants could purify the air inside a space capsule. The materials that go into building a space shuttle (or your home for that matter) will do some “off-gassing”.

This is when a product continues to release chemicals into the air after manufacturing.

Have you ever bought a new piece of furniture or carpet, brought it home, un-packaged it, and then got smacked by its terrible chemical-y smell. That is off-gassing.

The chemicals that are released during this off-gassing can include Volatile Organic Compounds (VOC’s) such as toluene, trichloroethylene, benzene, and octane. Plus, formaldehyde can be released by many household products.

It is chemicals such as these that can contribute to “sick building syndrome.” No, this isn’t when your building has a fever and is puking. It is when you (or other people) don’t feel well when you’re in the building.


Sick Building Syndrom: You may feel dizzy, itchy eyes, irritated nose, throat or eyes, congestion, skin rashes, headache, or many other types of symptoms.


What I found fascinating is that in the NASA paper (released 1989) – written by Bill Wolverton and others – is the authors talk about studies done by Dr. Tony Pickering of England.

In these studies Dr. Pickering determined that the most symptoms are experienced in buildings with tight seals that need to be mechanically ventilated (not natural drafts), and these building have the lowest levels of microorganisms.

So it is likely not the “bugs” in the buildings that are causing symptoms. But instead it is the lack of natural air transfer between inside the building and outside.



How do plants purify the air?

Plants can help purify the air in two major ways.

The first way is metabolizing toxic chemicals. This means the plant takes in the toxins and then chemically changes it and releases the byproducts (usually now harmless) back into the air.

And the second way is what they call sequestering toxic molecules. This means they take up the toxic chemicals, such as heavy metals, and incorporate it into their plant tissues.



In a way, the indoor air plants remind me of our liver enzymes. We have a system of enzymes in our liver called the Cytochrome P450 enzymes which are the major enzymes responsible for drug metabolism.

When we take a drug it goes to the liver and is processed (i.e. metabolized) by a particular enzyme. Each time we take that drug it is processed by the same type of enzyme.

Now, an enzyme in our liver may process more than one drug, but one enzyme doesn’t process all drugs.

So if a person is on 10 different medications they will have multiple enzymes working to help metabolize the drugs (to help clear them from our system).

And in this analogy we can think of a house plant like one of our liver enzymes.

A particular house plant may be able to process a few different chemical air impurities, but it may not be able to process ALL the different types of impurities in a house.

That is why it is necessary for you to have to have several different types of house plants to get the cleanest indoor air.

Because each species of house plant may be able to metabolize and detoxify a particular air impurity.


How to make your plants purify the air better

According to the work of the scientist Bill Wolverton, how well a plant cleanses the air can be improved by increasing the amount of air circulating past the roots of the plant.

And this is because in the root zone of the plant lives beneficial bacteria and other microorganisms that can help take the “bad stuff” from the air (which is now reaching them) and turn it into something the plant can use.

In some of their experiments at NASA they used activated carbon filters near the roots.




Top 10 List of Air-purifying House Plants

Enough of the small talk. You want to learn the best house plants for clean air.

This is from the work of Bill Wolverton. It is from his book, not his NASA document. The reference is at the bottom of the page.

Here is a link to the book on Amazon if you want your own copy.


Top 10 House Plants for clean air

  1. Areca palm (Dypsis lutescens)
  2. Lady palm (Rhapsis excelsa)
  3. Bamboo palm (Chamaedorea erumpens)
  4. Rubber Plant (Ficus elastica)
  5. Dracaena (“Janet Craig” variety)
  6. English ivy (Hedera helix)
  7. Dwarf date palm (Phoenix roebelenii)
  8. Ficus (Ficus macleilandii ‘Alii’)
  9. Boston fern (Nephrolepis exaltata)
  10. Dwarf Peace Lily (Spathiphyllum wallisii)



What was the criteria for their list?

The plants were ranked on these four criteria:

1)Chemical vapor removal
2) How easy it is to grow and maintain
3) How resistant the plant is to infestation by insects
4) Rate of transpiration


I like that ease of growing and maintenance is on the criteria. So then even notorious plant killers like me may have a chance.


What do these Air-purifying plants look like?

I do not have all of these indoor air-purifying plants at my house, but I do have some of them. And the ones I don’t have I’ve tracked down on the internet so you can see some pictures.


1. Areca palm (aka Butterfly palm, aka Dypsis lutescens)

This palm is like the dude who is caught at the border with multiple passports because this plant goes by many names.

But whatever you call it, it earned the top spot in Bill Wolverton’s book for air-purifying plants.

According to ourhouseplants.com this palm is fairly easy to grow indoors, but it doesn’t like direct sun and it doesn’t like very dark areas either.

So put it somewhere in between these extremes and this palm should do well.

Photo from Wikipedia by Mokkie
Link to Wikipedia page



2. Lady Palm (aka Rhapsis excelsa)

Here is another palm plant that can grow in low-light conditions, but according to plantcaretoday.com it will grow larger in bright conditions but not in direct sunlight.

Photo from Wikipedia by Mokkie
Link to Wikipedia page



3. Bamboo palm (Chamaedorea erumpens)

I had a bit of trouble finding this one online because some websites called the bamboo palm by other latin names, such as Chamaedorea seifrizii, and not Chamaedorea erumpens like they did in the paper I read.

But I did find some information on it from the University of Florida.

This air-purifying plant is native to the rain forests of Central America. In a rain forest with multi-layered canopies you can see why this plant likes the shade. It can do well in low-light conditions and its height is listed as 4 – 12 feet high.

If you have a bamboo palm and are having some difficulty with it, you may want to check out this webpage that lists common problems and what to do about them.

I’ll update with a picture once I get a copyright-free source.




4. Rubber Plant (Ficus elastica)

I bet you’ve either had one of these or your friends have. These things are very common as houseplants. I had my first one when I was in my early teens.

It’s great that they’re so common and sold by most plant stores because they are one of the best plants for clean air.

They can tolerate a wide variety of sunlight conditions, but it shouldn’t be overwatered. And I think that is why I’ve killed some of the rubber plants that I’ve had.

We currently have a rubber plant, but its tucked off in a corner, somewhat neglected. I was going to get a picture of it for this article, but it looked kind of sad. Not as robust and healthy-looking as the one below.

Image by Ирина Кудрявцева from Pixabay

In their native habitat of the jungles of India and Malaysia the rubber tree plant can grow up to 100 feet tall, but usually gets to be about 45 feet tall.

If you want a great air purifying plant you shouldn’t have to look too hard to find a rubber plant.




5. Dracaena deremensis “Janet Craig”( the Janet Craig variety)

This is the Janet Craig Dracaena plant when it is flowering. It is a durable indoor house plant that can do well in low-light conditions. According to plantcaretoday.com this plant can grow up to 15-feet tall in the wild, but is much smaller when indoors.

It is a nice, upright air purifying plant with nice shiny leaves that would go well in a corner (like in the photo below).

from Wikipedia. Photo by: Nickjhowe
Link to Wikipedia page



6. English ivy (aka Hedera helix)

Even though it is called “English ivy” it is native to Europe, western Asia and northern Africa.

It can look great as a hanging plant, or used to climb up trellises or other structures.

This plant grows well in many conditions, and is actually considered “invasive” in certain regions. So if you are in an area that considers it invasive don’t grow it outdoors, and check if you are even allowed it indoors.

Because it grows so well and has so much foliage it could be a good addition to your array of indoor air purifying plants.

I’m not a botanist, so I can’t verify, but I think it is English ivy that was growing up the side of my house. I had to chop it down and it left a bunch of “suckers” stuck to wall.

And in case you’re curious (like I was so I had to Google it), but it is not English ivy on the outfield wall of Wrigley Field in Chicago, it is apparently “Boston ivy.”

By Uwe H. Friese – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=373503


7. Dwarf Date Palm (aka Phoenix roebelenii, aka Pygmy date palm)

This single-stemmed palm can grow to be about 12 feet palm, and is apparently quite popular in Florida.

Below is a picture of the dwarf date palm being grown outdoors.

It has quite an amazing looking texture on its trunk.

It can spread quite wide (6-8 feet) so it may not be the best indoor plant for a small area, but it will be a good air purifying plant for a larger area.

Photo from Wikipedia by David Stang.
Link to Wikipedia and Commons license




8. Ficus (Ficus macleilandii ‘Alii’, aka banana leaf ficus)

This plant is native to China, southeast Asia and India. But it makes a good indoor plant that Bill Wolverton lists as being #8 on the list of best indoor plants for clean air.

Photo from Wikipedia by Luca Bove.
https://commons.wikimedia.org/wiki/File:Ficus-Maclellandii-Alii.jpg

According to plantcaretoday.com it is easier to grown and maintain compared to some of its ficus cousins like the Ficus benjamina.



9. Boston Fern (aka Nephrolepis exaltata, or Sword Fern)

The Boston fern is considered fast growing and easy to grow plant that can be used in hanging baskets or in pots.

Its fronds are usually 2-3 feet long.

I like how full and dense this fern looks.

Photo from Wikipedia. https://commons.wikimedia.org/wiki/File:Nephrolepis_exaltata_indoor0705c.jpg



10. Dwarf Peace Lily (Spathiphyllum wallisii)

The dwarf peace lily is usually 12-15 inches tall. So fairly compact compared to some of the other air purifying plants on this list. It is considered slow growing and has white flowers in the spring.

For more information on the dwarf peace lily, you can click here to see some information from the University of Florida.

By Jerzy Opioła – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=6467267




Uncertainty about Plants and clean air

I think most of use would agree that when we walk through the forest or jungle the air seems to smell cleaner.

Yet some people may have allergies to plants.

Some plants release their own small particulates into the air such as pollen.

And plants take VOC’s (like benzene) out of the air, but they also contribute their own VOC’s to the air.

Plus, the microorganisms may co-exist with the plant, such as certain types of fungus, may exacerbate some people’s allergies.

That is why you should monitor how you feel. If you feel worse after adding a certain plant to your indoor air space then perhaps you don’t tolerate that plant.




Future of using plants to purify indoor aid

More studies are being completed showing that particular plants work best at purifying the air of certain impurities.

And when they are combined with certain soil microorganisms the effectiveness of the air-cleansing is improved.

So in the future I believe there will be at-home testing for airborne chemicals and then you’ll select a houseplants(s) and certain microorganisms to detoxify your home’s particular air contaminant.

It will be similar to diagnosing a medical condition and then prescribing a treatment to treat that particular diagnoses.

Example from the NASA is that English ivy removed almost 90% of Benzene from a contaminated air chamber (the pot of only soil removed 20%), but it removed only 11% of another VOC called Trichloroethylene – and the soil-only pot removed 9%.

So English ivy did well at removing Benzene, but only about 2% more that just a pot of soil when it comes to purifying the air of Trichloroethylene.

In the future if there is inexpensive testing for your home’s indoor air pollutants you’ll be able to select a plant that does well at eliminating that particular offender.



Conclusion

There are a lot of low-light indoor house plants that will help purify the air inside your new energy-efficient home.

This list of Top 10 air purifying plants is just a start.

Pick a plant that suits your family’s needs – such as is it toxic to pets? And a plant that fits the space you have available to grow it.



References

The NASA paper. Wolverton, B.C., Johnson, A., Bounds, K. “Interior Landscape Plants for Indoor Air Pollution Abatement.” Available online.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930073077.pdf


This list of Top 10 plants was included in this article https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3230460/#r17

and it references

Wolverton BC. How to Grow Fresh Air: 50 House Plants that Purify Your Home or Office. New York, NY:Penguin Books (1997). [Google Scholar]

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