When the indoor air makes you wheeze, you can spend $300 to $1000 for an HEPA air purifier. It will add a level of noise, take up space, and probably look ugly, too. Or maybe it’s time to remember the quietly elegant and useful spider plant.
In 1989, the news broke that NASA research discovered the power of the humble spider plant, Chlorophytum comosum, to clear the air. It removed formaldehyde, benzene, xylene, carbon monoxide and other impurities. It grabbed particulates from the air as well.[i]
After that research came out, spider plants graced every trendy bistro, bar, and suburban home in sight. During the 1990s, spider plants hung in the pursuit of clean air were so common, there was a backlash. Now, three decades down the road from the era of spider plant mania, the lead scientist on the NASA project, Bill Wolverton, is once again pushing indoor plants as a “way to grow clean air,” and he has a point.
Maybe it’s time to reconsider the poor spider plant along with others that do the same good work.
Here’s what to know…
Why You Should Have a Spider Plant (and Others) at Home
Some of the harmful indoor air pollutants most commonly present in homes are formaldehyde, benzene, nitrogen dioxide, carbon monoxide and particulate matter.
Dust (a.k.a. particulate matter) is obvious. But is your own home likely to have formaldehyde or other industrial-sounding pollutants?
Formaldehyde is probably there because it comes from building materials like some wooden floors and paneling as well as furniture and paints. Furniture made with MDF or fiberboard is a rich source. That product lurks at the center of most home entertainment units, home office furniture, shelving, and drawer components.[ii]
Fuel burning appliances like gas stoves and fireplaces are another source. Common chores like cleaning, frying meat, ironing, and using fireplaces) also bring formaldehyde into your home.
Carbon monoxide enters our homes via fireplaces, gas stoves and furnaces. Running the car in an attached garage is another source. Though a home monitor will warn you of dangerous levels, it’s best to breath as little carbon monoxide as possible. That’s where a spider plant is especially useful.
Benzene in your home comes from plastics, resins, detergents, pesticides, laundry soap, tobacco smoke and furniture wax.
Clear the Air
Plants make the home seem fresher, and there are a couple of reasons for that. Most homes have very little humidity, and plants can help balance that condition. But most of all they remove particulates.
In 2014, a pair of scientists at the University of Warsaw in Poland investigated what would happen if they put spider plants in five different kinds of indoor spaces. They chose a dental clinic, a perfume-bottling room, a suburban house, an apartment and an office,
By the time of their experiment, hundreds of plants had been tested for “phytoremediation,” which roughly translates as “plants repairing the world.” But the previous work had focused on gases. These researchers wanted to look at solids—the stuff they call “particulate matter” and we call “dust.”’
They placed potted spider plants in the rooms for 2 months. They also put aluminum plates in the rooms to track the dust collecting on inanimate surfaces.
As you would expect, dust fell on everything. But the spider plants gathered significantly more than the aluminum plates did. The plants were actively accumulating particulate matter in indoor air. It was not just a “dust falling on houseplant” process.
Make It Safe
In another study, a group a group of environmental scientists and chemists at Nanchang Hangkong University in China filled in some detail on spider plants’ ability to rid the air or noxious gases. They found that spider plants can tolerate 8ppm of formaldehyde concentration for as long as 7 days and continue working. After that, they need to have 10-15 days of self-recovery.
The spider plants not only tolerated fairly high levels of pollution they were surprisingly effective. At 1 ppm density for formaldehyde, a spider plant showed it could clear 71% -84% of the gas from the air during the day and 36% - 64% at night. [iii]
In case you are wondering, this means a spider plant would take care of your home because the average formaldehyde level in older homes is below 1 ppm. Levels are much higher in new manufactured homes because of the building materials, but even there the average level is only about 0.04 ppm. [iv]
Where You Should Put Your Spider Plant
Your spider plant must be in an area where it will receive indirect lighting, as direct sunlight will scorch its leaves. You should also steer clear from putting it near your pool or your fluoridated tap water to avoid splashes to your spider plants.
These plants clear the air best nearest the plant. So if you sit in a particular spot like a favorite chair or you work at your desk, that’s a good place to put a plant.
Ideally, according to NASA, you should have one plant for every 100 square feet in your home. That’s a bit much for most of us. One plant in each room you use frequently should make a difference.
If you still feel like your home is stale and dusty, you may want an air purifier as well as houseplants. But be aware that even a high-end air purifier with HEPA filter only removes particulates, not gases like formaldehyde.
How to Care For Your Plant
Spider plants are easy to grow. They thrive in at any indoor temperature from cool to warm. Just make sure not to water them with fluoridated or chlorinated water as that can cause tip dieback or the browning of the tips of its leaves. If your tap is chlorinated, leave a jug water on the counter so it can off-gas. Or you can use a simple filtered pitcher like a Brita. That does not remove fluoridation, however. In that case, you can buy spring water for your plants. If you’re feeling especially virtuous, you can collect some rainwater to use on them.
Spider Plant Is Not Alone
Spider plants are well studied, but others do a good job, too. One of the other best indoor plants for clearing the air is Epipremnum aureum, commonly known as pothos.
While spider plants are easy to care for, the pothos will survive even the most brown-thumbed gardener. It also grows well in bright light, so you can use it in areas where spider plants don’t do as well. This hardy plant can also tolerate such low light levels that you can put it in a windowless bathroom and expect it to thrive.
Actually, for all the good press the spider plant got right after the NASA study was published, the banana plant, English ivy, sansivieria (snake plant), dracaena, and peace lily were even more efficient at removing formaldehyde.
Anything but silk or plastic fakes will surely help clear the air, look great, and cost little.
[iii]Li J, Zhong J, Zhan T, Liu Q, Yan L, Lu M. Indoor formaldehyde removal by three species of Chlorphytum Comosum under the long-term dynamic fumigation system. Environ Sci Pollut Res Int. 2019 Dec;26(36):36857-36868. doi: 10.1007/s11356-019-06701-x. Epub 2019 Nov 19. PMID: 31745795.
[iv]California Air Resources Board.