After receiving information on how to eliminate the insects from her bug-infested very large spider plant, a woman at the Anacortes Master Gardener Clinic decided she'd throw it out . I reminded her the spider plants helped clean the air inside her home.
She replied it was OK, she had a broad-leafed plant that supposedly did the same thing. That got me thinking.
Frankly to my knowledge, spider plants are the only plants noted for cleaning the air. However, if there was one, common sense said there may be more. To the computer!
I came across a report published in 1989, Interior Landscape Plants for Indoor Air Pollution Abatement, of a study by NASA and the Associated Landscape Contractors of America (ALCA) with excellent news for homeowners and office workers everywhere.
Common indoor plants may provide a valuable weapon in the fight against the rising levels of indoor air pollution. Those plants in your home or office are not only decorative, but NASA scientists are finding them to be surprisingly useful in absorbing potentially harmful gases and cleaning the air inside modern buildings.
NASA also stated that newer homes and buildings, designed for energy efficiency, are often tightly sealed to avoid energy loss from heating and air conditioning systems. More over, synthetic building materials used in modern construction have been found to produce potential pollutants that remain trapped in these unventilated buildings.
Three chemicals: Formaldehyde, Benzene, and Trichloroethylene are causing the most concerns.
Formaldehyde is used in many building materials, including particle board and foam insulations. Many cleaning products contain this chemical.
Benzene is a common solvent found in oils and paints.
Trichloroethylene is used in paints, adhesives, inks and varnishes.
While NASA found that some plants were better than others for absorbing these common pollutants, all of the plants had properties useful in improving indoor air quality.
NASA also noted some plants are better than others in treating certain chemicals.
For example, English ivy, gerbera daisies, pot mums, peace lily, bamboo palm, and Mother-in-law’s tongue are very effective in treating Trichloroethylene.
NASA found that bamboo palm, mother-in-law’s tongue, dracaena marginata, golden pothos, and green spider plant worked well for filtering formaldehyde.
After conducting the study NASA and ALCA came up with a list of the most effective plants for treating indoor air pollution. All of these are readily available from your local nursery.
1. Philodendron scandens “oxycardium”, heartleaf philodendron
2. Philodendron domesticum, elephant ear philodendron
3. Dracaena fragrans ‘Massangeana’, cornstalk dracaena
4. Hedra helix, English ivy
5. Chlorophytum comosum, spider plant
6. Dracaena deremensis ‘Janet Craig’, Janet Craig dracaena
7. Dracaena deremensis ‘Warneckii’, Warneck dracaena
8. Ficus benjamina, weeping fig
9. Epipiremnum aureum, golden pothos
10. Spathiphyllum ‘Mauna Loa’, peace lilly
11. Philodendron selloum, selloum philodendron
12. Aglaonema modestum, Chinese evergreen
13. Chamaedorea sefritzii, bamboo or reed palm
14. Sansevieria trifasciata, snake plant
15. Dracaena marginata, red-edged dracaena
For an average home of under 2,000 square feet, the study recommends using at least fifteen samples of a good variety of these common houseplants to help improve air quality. They also recommend that the plants be grown in six inch containers or larger.
In How to Grow Fresh Air, published by Penguin Books in 1997, author Dr. B. C. Wolverton lists the same plants as well as many others and rates plants as to their effectiveness against all sorts of the semi-unpronounceable, nasty sounding chemical vapors listed above.
He also addresses ease of growth, maintenance, resistance to insect infestation and transpiration rate.
Pour yourself a hot cup of coffee, boot up your computer and Google "Plants that clean the air."
You will learn more than you probably ever wanted to know on this subject. Just about every study I read referred to the NASA study. For me, this brought what was basically an Urban Legend into the realm of truth.
Just a note: When you are searching for information online, check the source. For plants and such I look to sources such as county extensions, universities, USDA and the like. If the source is "Aunt Hattie’s household hints" don't go there.