Debunking NASA study on air-cleaning plants

Tue. Jan. 9, 2024

Click on the link below to listen to today’s Garden Bite: Debunking NASA study on air-cleaning plants

Over 30 years ago, in 1989, NASA scientist Bill Wolverton claimed that household plants could provide a “promising” solution to indoor air pollution.

Decades later that report is doused with cold water. And for the record, not from me but from those WELL above my pay grade!

Including the American Lung Association. In part they said that This NASA study showed that plants did clean the air in a closed, limited environment or chamber. Other studies have confirmed2 that plants can remove harmful gases, such as formaldehyde. BUT, and it’s a big one…  The problem is that our indoor environments are not like space stations. What works in a chamber study does not necessarily translate into real life settings.

Monstera and Black Tie begonia

One difference results from trying to scale-up from a test chamber to real life. The sample sizes used in testing, such as in the NASA study, are often very small so their findings don’t translate well into real-world experiences.

 Read the full article HERE. In other words, we would have to have a WALL of plants to make a real contribution to “cleaner” air according to LiveScience. That said, there’s more to it.

You may already know that air quality is affected by carbon dioxide. Carbon dioxide absorbs and radiates heat. Without it, our planet would be way colder than our worst Minnesota winter! (Think Ice Age) However, fossil fuel burning, deforestation and cement construction (that one threw me) are amping up our release of carbon dioxide way more than our atmosphere can take which means we’re seeing our climate change much faster than ever before. I have included a  diagram from UCAR, the Center for Science Education.

 Here is a little more on understanding Climate Change from climate.gov/news.

Just for grins…here’s a photo of a monstera deliciosa in its native habit in the Lisbon (Portugal) Botanical Gardens in Portugal that I took in October 2023.

Monstera deliciosa Portugal Botanical Gardens Lisbon – not enough room in my house for this beast!

 While those of us in cold climates have often heard that plants could help us avoid becoming ill by “clearing” our indoor air, the pandemic added fuel to that notion and sparked a huge increase in houseplant love. Nothing wrong with houseplant love but you have to consider their limitations and that THEY need care also. Here’s what they DO provide…

  • They make us feel good. Our mental health is affected in a significantly positive way, especially during the cold, dark days of winter.
  • They reduce stress (unless you’re the type to freak out if a plant dies). Please, we’ve all experienced that, it’s okay. Learn about the plants that will work in YOUR home!
  • They connect us. We talk with other houseplant folks about why our plants died, we share notes and experiences. We share plants!
  • They are beautiful and they DO offer a very small benefit to our air quality.
  • As most indoor plants in our Minnesota climate are from the tropics, it’s like we’re on vacation. Okay, that’s probably a stretch but work with me here! ?
Pothos ‘Silver Satin’


Houseplants are great, but they will not purify your indoor air. If you really want to make sure your indoor air is “clean” then look into purchasing an Air Purifier. 

Hopefully your holidays were filled with the aromas of your favorite dishes along with family and friends! Well, not THEIR aroma, but their presence (presents). ?

Cheers to the houseplants that cheer us up!

Philodendron ‘Hope’