University of Illinois Extension

Ferns Freshen Indoors

Ferns bring a room to life any time of year.

Nancy Pollard

"In airtight winter homes, they also can be champions at filtering the air," said Pollard. "Of 86 plants tested, ferns topped the list at formaldehyde removal. In fact, seven of the top nine excellent performers were ferns."

The other great filterers of formaldehyde were (#7) lavender and (#9) – grandma's favorite – geraniums (Pelargonium sp.) These findings were reported by Kwang Jin Kim and associates in an article published in the October 2010 issue of HortScience.

Other researchers also found ferns ranked in the top 15 percent at air purification compared to woody plants and other herbaceous plants.

"Researchers learned for instance, that a fern can be 50 times more effective indoors at removing formaldehyde than some other common houseplants tested, though all had a positive effect," Pollard noted. "Formaldehyde, a volatile organic compound (VOC), can build up in well-insulated modern homes.

"VOCs may originate from a variety of indoor sources such as particle board, plywood, carpet, paper products, tobacco smoke, and adhesives."

Formaldehyde removal by plants was five times faster in light than in dark according to other researchers, so artificial lights in winter could help your plants work longer and harder at cleaning the air.

Fern"In addition to the plants removing formaldehyde, soil microorganisms inhabiting healthy potting soil seem to also clean up the air," she said. "The bottom line is ferns–and other houseplants – freshen the air we breathe. Get some plants, give them some light, and take in a deep breath of fresh air."