The 15 Best Plants for Really Clean Air (and What the Science Actually Says)
The 15 Best Plants for Really Clean Air (and What the Science Actually Says)
<small>Snake plant (Sansevieria trifasciata 'Laurentii'). Photo: Mokkie, CC BY-SA 3.0, via Wikimedia Commons.</small>
Most of us spend the bulk of our day indoors, and the air in there is often worse than the air outside. According to the U.S. Environmental Protection Agency, concentrations of many volatile organic compounds (VOCs) are consistently higher indoors, up to ten times higher than outdoors, and the EPA's TEAM studies found about a dozen common pollutants at 2 to 5 times higher levels inside homes than outside.
Houseplants have become the go-to "natural air purifier." Some of that reputation is earned, and some of it is hype. This guide covers both: the 15 plants with the strongest lab track record for removing indoor pollutants, how to care for each, which ones are safe around pets, and how to combine plants with the habits that actually move the needle on indoor air quality.
Quick navigation: The science Β· The 15 plants Β· Comparison table Β· Pet safety Β· How to get the most from your plants Β· FAQ
What the Science Really Says
The NASA Clean Air Study
The modern "air-purifying plant" idea traces back to 1989, when NASA and the Associated Landscape Contractors of America tested common houseplants as a way to clean air in sealed environments like space stations (NASA Clean Air Study, Wikipedia). NASA scientist Bill Wolverton screened a dozen common houseplants, from the gerbera daisy to the bamboo palm, for their ability to remove household toxins like formaldehyde from a sealed chamber (NASA Spinoff).
The pollutants tested were benzene, formaldehyde, and trichloroethylene, and later related studies added xylene, toluene, and ammonia (Wikipedia). Those chemicals come from everyday products. The EPA lists paints and lacquers, cleaning supplies, building materials and furnishings, printers and copiers, glues, and permanent markers among common VOC sources.
The reality check
In 2019, Drexel University researchers Michael Waring and Bryan Cummings reviewed a dozen studies spanning 30 years and found that normal ventilation in homes and offices dilutes VOCs much faster than plants can remove them (Drexel University). By their math, you would need between 100 and 1,000 plants per square meter of floor space to match a building's air handling system or a couple of open windows (Drexel University).
A big reason for the gap: most lab tests put a single plant in a sealed chamber of one cubic meter or smaller, injected one chemical, and tracked it over hours or days (Drexel University). A real living room is far bigger and far leakier. Interestingly, a 2004 study found that microorganisms in potting soil do much of the benzene removal, with some plant species contributing as well (Wikipedia).
So why bother with plants?
Because the right plants are still a smart part of a healthy home. They are proven VOC absorbers in controlled settings; they add humidity, and they make spaces more pleasant to live and work in. The key is to treat them as one layer of a clean-air strategy, alongside ventilation, source control, and filtration, not as a replacement for them. We cover that strategy in detail in our guide to improving indoor air quality at home.
The list below ranks plants by their documented pollutant-removal results, then by how easy they are to keep alive, because a dead plant cleans nothing.
The 15 Best Plants for Clean Air
Pollutant figures below come from the comparison table of NASA and similar studies compiled on Wikipedia's NASA Clean Air Study page, reported in micrograms removed per hour (Β΅g/h) under lab conditions. Pet-safety notes are based on the ASPCA's toxic and non-toxic plant database.
1. Bamboo Palm (Chamaedorea seifrizii)
<small>Bamboo palm. Photo: KENPEI, CC BY-SA 3.0, via Wikimedia Commons.</small>
The bamboo palm is the all-around champion in the NASA data, posting the highest formaldehyde number on the list at 3,196 Β΅g/h, plus 1,420 Β΅g/h of benzene and 688 Β΅g/h of trichloroethylene (Wikipedia). It also removes xylene and toluene.
Light: Medium to bright indirect light; tolerates lower light.
Water: Keep soil lightly moist, never soggy.
Size: 4 to 8 feet indoors, making it a great floor plant.
Pets: Non-toxic to cats and dogs.
Best spot: Living rooms and offices with new furniture or flooring.
2. Snake Plant (Sansevieria trifasciata / Dracaena trifasciata)
The snake plant is the best "set it and forget it" air plant. It removed 1,196 Β΅g/h of benzene, 1,304 Β΅g/h of formaldehyde, and 405 Β΅g/h of trichloroethylene in testing (Wikipedia), and the variegated 'Laurentii' variety was one of the original 12 plants NASA tested.
Light: Low to bright indirect; very forgiving.
Water: Every 2 to 4 weeks; let soil dry completely.
Size: 1 to 4 feet.
Pets: Toxic to cats and dogs.
Best spot: Bedrooms and dim corners. See our list of low-light houseplants for more options.
3. Peace Lily (Spathiphyllum)
<small>Peace lily. Photo: W.carter, CC BY-SA 4.0, via Wikimedia Commons.</small>
The peace lily is one of the few plants on the list that tackled all five pollutant categories, including ammonia. It removed 1,725 Β΅g/h of benzene, 674 Β΅g/h of formaldehyde, and 1,128 Β΅g/h of trichloroethylene (Wikipedia).
Light: Low to medium indirect light.
Water: Keep evenly moist; it droops dramatically when thirsty, then perks right back up.
Size: 1 to 3 feet.
Pets: Toxic to cats and dogs.
Best spot: Bathrooms and kitchens, where cleaning products are used most.
4. Dracaena 'Janet Craig' (Dracaena fragrans 'Janet Craig')
<small>Dracaena 'Janet Craig' in bloom. Photo: Nickjhowe, CC BY-SA 3.0, via Wikimedia Commons.</small>
'Janet Craig' is a quiet overachiever with formaldehyde removal of 1,361 to 2,037 Β΅g/h, plus 1,082 Β΅g/h of benzene and 764 Β΅g/h of trichloroethylene (Wikipedia). Its glossy, dark leaves handle office lighting well.
Light: Low to medium indirect.
Water: When the top inch of soil is dry. Use filtered water if leaf tips brown.
Size: 3 to 6 feet.
Pets: Toxic to cats and dogs.
Best spot: Home offices near printers.
5. Red-Edged Dracaena (Dracaena marginata)
<small>Dracaena marginata. Photo: Wikimedia Commons, CC BY-SA 3.0.</small>
The dragon tree's spiky, architectural look hides strong numbers: 1,264 Β΅g/h of benzene, 853 Β΅g/h of formaldehyde, and 1,137 Β΅g/h of trichloroethylene (Wikipedia).
Light: Bright indirect light keeps the red edges vivid.
Water: Let the top half of the soil dry out.
Size: 5 to 8 feet over time.
Pets: Toxic to cats and dogs.
Best spot: Modern living spaces with high ceilings.
6. Boston Fern (Nephrolepis exaltata 'Bostoniensis')
<small>Boston fern. Photo: Homer Edward Price, CC BY 2.0, via Wikimedia Commons.</small>
The Boston fern is a formaldehyde specialist at 1,863 Β΅g/h, one of the top results on the entire list, and it also removes xylene and toluene (Wikipedia). Its feathery fronds also release a lot of moisture, which helps in dry winter homes.
Light: Bright indirect.
Water: Keep consistently moist; mist or use a pebble tray.
Size: 1 to 3 feet wide; great in hanging baskets.
Pets: Non-toxic to cats and dogs.
Best spot: Humid bathrooms with a window.
7. Florist's Chrysanthemum (Chrysanthemum morifolium)
<small>Florist's chrysanthemum 'Mei-Kyo'. Photo: W.carter, CC BY-SA 4.0, via Wikimedia Commons.</small>
Pot mums are the flowering powerhouse of the list, removing 3,205 Β΅g/h of benzene and 1,450 Β΅g/h of formaldehyde, along with xylene, toluene, and ammonia (Wikipedia). The catch: they are usually short-lived indoors, so think of them as a seasonal boost.
Light: Bright light, a few hours of direct sun.
Water: Keep moist; do not let it dry out while blooming.
Size: 1 to 2 feet.
Pets: Toxic to cats and dogs.
Best spot: A sunny windowsill in fall.
8. Gerbera Daisy (Gerbera jamesonii)
<small>Gerbera daisy. Photo: Alexey Yakovlev, CC BY-SA 4.0, via Wikimedia Commons.</small>
The gerbera daisy posted the single highest benzene number in the dataset at 4,486 Β΅g/h, plus 1,622 Β΅g/h of trichloroethylene (Wikipedia). It is a cheerful, colorful option and one of the safest flowering choices for pet owners.
Light: Bright light with some direct sun.
Water: Water at the base when the top inch is dry; avoid wetting the crown.
Size: 8 to 18 inches.
Pets: Non-toxic to cats and dogs.
Best spot: Sunny kitchen or dining room windows.
9. English Ivy (Hedera helix)
<small>English ivy. Photo: kallerna, CC BY-SA 4.0, via Wikimedia Commons.</small>
English ivy is a well-rounded performer, removing 579 Β΅g/h of benzene, 402 to 1,120 Β΅g/h of formaldehyde, and 298 Β΅g/h of trichloroethylene (Wikipedia). Grow it indoors in a pot or hanging basket; outdoors, it can be invasive in many regions.
Light: Medium to bright indirect.
Water: Keep slightly moist; prefers cooler rooms.
Size: Trailing vines up to several feet.
Pets: Toxic to cats and dogs.
Best spot: High shelves and hanging baskets, out of reach of pets and kids.
10. Weeping Fig (Ficus benjamina)
One of NASA's original 12, the weeping fig removed 940 Β΅g/h of formaldehyde plus xylene and toluene (Wikipedia). It is a classic indoor tree, but it hates being moved and may drop leaves when relocated.
Light: Bright indirect; consistent placement.
Water: When the top inch is dry.
Size: 3 to 10 feet indoors.
Pets: Toxic to cats and dogs.
Best spot: A bright corner it can stay in permanently.
11. Chinese Evergreen (Aglaonema modestum)
<small>Chinese evergreen. Photo: Mangostar, CC BY-SA 3.0, via Wikimedia Commons.</small>
Chinese evergreen removed 604 Β΅g/h of benzene and 183 Β΅g/h of formaldehyde in testing (Wikipedia). It is one of the most shade-tolerant plants you can buy, which makes it ideal for rooms where other plants struggle.
Light: Low to medium indirect.
Water: When the top 1 to 2 inches are dry.
Size: 1 to 3 feet.
Pets: Toxic to cats and dogs.
Best spot: Interior rooms and north-facing windows.
12. Lady Palm (Rhapis excelsa)
<small>Lady palm. Photo: Aris riyanto, CC BY-SA 4.0, via Wikimedia Commons.</small>
The lady palm removed 876 Β΅g/h of formaldehyde and was one of the few plants reported to remove ammonia, a common ingredient in household cleaners (Wikipedia). It grows slowly and is famously low-maintenance.
Light: Medium indirect; tolerates low light.
Water: Let the top inch dry between waterings.
Size: 4 to 6 feet.
Pets: Non-toxic to cats and dogs.
Best spot: Entryways and laundry rooms.
13. Spider Plant (Chlorophytum comosum)
<small>Spider plant. Photo: Ω
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The spider plant removed 560 Β΅g/h of formaldehyde, plus xylene and toluene (Wikipedia). It is nearly indestructible, produces baby "spiderettes" you can root for free, and is one of the best choices for homes with pets.
Light: Medium to bright indirect.
Water: When the top inch is dry.
Size: 1 to 2 feet, trailing.
Pets: Non-toxic to cats and dogs.
Best spot: Hanging baskets in kitchens and kids' rooms. More picks in our roundup of pet-safe houseplants.
14. Areca Palm (Dypsis lutescens)
<small>Areca palm. Photo: Ping an Chang, CC BY-SA 4.0, via Wikimedia Commons.</small>
The areca palm's main documented strength is removing xylene and toluene (Wikipedia), the solvents found in paints, adhesives, and nail polish. It is also a strong natural humidifier and a pet-friendly statement plant.
Light: Bright indirect.
Water: Keep lightly moist in spring and summer; less in winter.
Size: 6 to 7 feet indoors.
Pets: Non-toxic to cats and dogs.
Best spot: Freshly painted rooms or craft spaces.
15. Golden Pothos (Epipremnum aureum)
<small>Golden pothos. Photo: Mokkie, CC BY-SA 3.0, via Wikimedia Commons.</small>
Pothos earns its spot mainly through xylene and toluene removal (Wikipedia) and its near-unkillable nature. It is the best beginner plant on this list and grows fast, which means more leaf surface over time.
Light: Low to bright indirect.
Water: When the top 1 to 2 inches are dry.
Size: Vines can trail 6 to 10 feet.
Pets: Toxic to cats and dogs.
Best spot: Bookshelves, cabinet tops, and hanging planters. New to plants? Start with our beginner's guide to houseplant care.
At-a-Glance Comparison Table
Values are lab results in Β΅g/h compiled from NASA and similar studies (Wikipedia). "Yes" means removal was reported. Pet safety per the ASPCA.
Pet Safety Cheat Sheet
If you share your home with cats or dogs, safety matters as much as performance. Always double-check any plant in the ASPCA plant database before bringing it home.
Pet-friendly picks: Bamboo palm, Boston fern, gerbera daisy, lady palm, spider plant, areca palm.
Keep out of reach: Snake plant, peace lily, dracaenas, chrysanthemum, English ivy, weeping fig, Chinese evergreen, pothos.
How to Get the Most Clean Air From Your Plants
Plants work best as part of a layered approach. Here is how to stack the odds in your favor.
Control the source first. Choose low-VOC paints, store solvents and cleaners in a garage or shed, and air out new furniture. The EPA notes that VOCs can linger long after a product is used, and stored products can keep releasing them.
Ventilate. Since air exchange dilutes VOCs much faster than plants remove them (Drexel University), open windows when weather allows and run kitchen and bath exhaust fans.
Add filtration. A HEPA air purifier handles particles like dust and pollen; models with activated carbon help with odors and gases. Compare options in our air purifier buying guide.
Group plants in the rooms you use most. Clustering several plants in a bedroom or home office maximizes leaf and soil surface where you breathe most.
Keep leaves clean. Wipe dusty leaves monthly with a damp cloth so they can photosynthesize and exchange gases efficiently.
Don't overwater. Soggy soil breeds mold, which works against clean air. Use pots with drainage holes and water only when the plant needs it.
Repot every one to two years. Since soil microbes do a lot of the work (Wikipedia), fresh, healthy potting mix helps.
Best Plants by Room
For design ideas, see our post on decorating with indoor plants.
Frequently Asked Questions
How many plants do I need to clean the air in a room?
There's no magic number. Lab studies show plants absorb VOCs, but researchers at Drexel estimated that matching normal building ventilation would take 100 to 1,000 plants per square meter (Drexel University). A practical goal is a few healthy, medium-to-large plants in each main room, combined with ventilation and filtration.
Which plant removes the most formaldehyde?
In the compiled study data, the bamboo palm leads at 3,196 Β΅g/h, followed by Dracaena 'Janet Craig' (up to 2,037 Β΅g/h) and the Boston fern (1,863 Β΅g/h) (Wikipedia).
Do snake plants really give off oxygen at night?
Snake plants use a type of photosynthesis (CAM) that opens their pores at night, so they are a popular bedroom pick. The oxygen added is small, though, so enjoy them for their looks and toughness rather than as an oxygen source.
Are air-purifying plants better than an air purifier?
No. A mechanical air purifier and good ventilation will do far more for indoor air than plants alone (Drexel University). Plants are a healthy, beautiful complement.
What's the easiest air-purifying plant for beginners?
Snake plant, Pothos, and spider plant are the hardest to kill. If you have pets, start with the spider plant.
The Bottom Line
The best plants for really clean air are the ones that combine a strong lab track record with easy care: bamboo palm, snake plant, peace lily, and the dracaenas lead the pack, while spider plants, Boston ferns, and palms are the top pet-safe choices. Pair them with fresh air, smart product choices, and a good filter, and you'll have a home that looks greener and breathes easier.
Keep reading:
How to Improve Indoor Air Quality at Home
12 Low-Light Houseplants That Thrive Anywhere
Pet-Safe Houseplants for Cat and Dog Owners
Sources
U.S. EPA, "What are volatile organic compounds (VOCs)?" https://www.epa.gov/indoor-air-quality-iaq/what-are-volatile-organic-compounds-vocs
NASA Spinoff, "NASA Plant Research Offers a Breath of Fresh Air." https://spinoff.nasa.gov/Spinoff2019/cg_7.html
Wikipedia, "NASA Clean Air Study" (pollutant-removal comparison table). https://en.wikipedia.org/wiki/NASA_Clean_Air_Study
Drexel University, "Study: Actually, Potted Plants Don't Improve Air Quality" (Cummings & Waring, Journal of Exposure Science and Environmental Epidemiology, 2019). https://drexel.edu/news/archive/2019/november/potted-plants-do-not-improve-air-quality
ASPCA, "Toxic and Non-Toxic Plants." https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants
All photos via Wikimedia Commons under the Creative Commons licenses noted in each caption.