So just stop with the claims. I thought this—well, let’s call it an exaggeration rather than a myth—had died down, but no. It cropped up in a recent enewsletter from a source I’d have thought knew better: the National Garden Bureau. Yes, the NGB is all about marketing, but it generally sticks with announcing All-America Selections, promoting the work of longtime gardening experts, surveying gardeners, and so on. Mind you, the word “might” was used, but that came after “And we all know they can help ‘clear the air.’” This is by no means a forthright statement that plants do any true air cleaning and it wasn’t meant to be.
The people at NGB know just as well as most of us that a 1989 NASA study about plants cleaning volatile organic compounds (VOCs) from interior spaces has been found to be fine as far as it went, but its conditions were far from that to be found in any home. As this article notes, “To reduce VOCs enough to impact air quality would require around 10 plants per square foot. In a small 500-square foot apartment, that’s 5,000 plants.”
I know there are a lot of fanatical houseplant collectors out there, but that number sounds a bit high. Full disclosure: I bought into all the air-cleaning at one point myself, until I saw better data.
I could cite studies about this all day long—here’s the one the NatGeo article I mentioned above uses—but that’s not the point. At all. Houseplants are wonderful. A boatload of positive arguments can be made that have nothing to do with air-cleaning. They provide beauty and softening effects to interior spaces. To some degree, they bring nature inside. Many of them even make rooms smell nicer, as the tulips I’m forcing in my dining room (at top) do. Though I won’t claim psychological benefits for all—those studies exist as well—I know they make me feel happier.
We don’t need to oversell houseplants.