Best Houseplants to Improve Indoor Air Quality

By: Julie Day


Golden Pothos (Epipiremnum aureum)

We all remember learning in science class that plants “breathe” by taking in carbon dioxide and releasing oxygen, which is why forests are so important in maintaining the delicate balance of the earth’s atmosphere. But did you know that certain tropical houseplants can also remove and process other, more harmful, chemicals from the air inside your home?


Dracaena deremensis ‘Warneckii’

Toxic Chemicals in Household Air

Homes and office buildings today are often more polluted than the outdoors. Modern buildings are tightly sealed and insulated to make them energy efficient, and they’re also full of synthetic materials that emit harmful gases and chemicals into the air. The result is a sealed bubble of unclean air that can lead to what is known as “Sick Building Syndrome.” Some of the most common indoor pollutants are:

  • Formaldehyde: Commonly used in a number of items including particle board, pressed wood, foam insulation, cleaning products, and treated paper or fabric. If your home or office contains particle-board furniture, grocery bags, tissues, paper towels, or anything that has been treated to make it stiffer, wrinkle-resist, fire retardant, or water-repellent, then you’re likely to have formaldehyde in the air.
  • Benzene: A solvent used in manufacturing paints, inks, plastics, rubber, dyes, pharmaceuticals, and detergents.
  • Trichloroethane: Can be found in adhesives, varnishes, paints, and used in dry-cleaning.

At the very least, chemicals like these can irritate the eyes and skin, lead to allergic reactions, and cause headaches. At worst, they’ve been linked to more serious problems including asthma, cancer, anemia, organ damage, and birth defects. Given the pervasive presence of these chemical in our homes, it can be difficult to create an environment that is free of them.


Ficus tree (Ficus benjamina)

Research by NASA and ALCA

In the late 1980s, a two-year research study was conducted by NASA and the Associated Landscape Contractors of America (ALCA) to investigate ways to create healthy, breathable environments in outer space. They found that certain tropical plants, commonly used as houseplants, were quite effective in removing formaldehyde, benzene, and trichloroethane from the air and replacing it with breathable oxygen.

All plants provide some benefit to air quality, but their research showed that tropical plants (grown as houseplants in cooler climates) are particularly effective at processing gases and chemicals. Because they grow in dense rainforests with very little light, they have evolved to be very efficient at photosynthesis, which includes the absorption of gases from the air. In addition, as plants transpire (emit water from the leaves), air is drawn down around the roots, where root microbes quickly adapt and begin “eating” the harmful chemicals that are absorbed.

The result was a list of recommended plants for reducing toxic chemicals in indoor environments. Most are common houseplants that you should be able to find at your local garden center. Two of the recommended plants (Gerbera Daisy and Pot Mum) are ornamental blooming plants that are frequently brought indoors for seasonal decorations.


Heartleaf Philodendron (Philodendron scandens ‘Oxycardium’)

Top Plants for Reducing Indoor Air Pollution

  • Bamboo Palm (Chamaedorea seifrizii)
  • Chinese Evergreen (Aglaonema modestum)
  • Dracaena (Dracaena sp.). Especially Red-Edged Dracaena (Dracaena marginata), Janet Craig (Dracaena deremensis ‘Janet Craig’), Warneckii (Dracaena deremensis ‘Warneckii’), and Corn Plant (Dracaena fragrans ‘massangeana’)
  • English Ivy (Hedera helix)
  • Ficus, or Weeping Fig (Ficus benjamina)
  • Gerbera Daisy (Gerbera jamesonii)
  • Golden Pothos (Epipiremnum aureum)
  • Peace Lily (Spathiphyllum sp.)
  • Philodendron (Philodendron sp), particularly Heartleaf (Philodendron scandens ‘oxycardium’), Selloum (Philodendron selloum), and Elephant Ear Philodendron (Philodendron domesticum)
  • Pot Mum (Chrysanthemum morifolium)
  • Snake Plant, or Mother-In-Law’s Tongue (Sansevieria trifasciata ‘Laurentii’)
  • Spider Plant (Chlorophytum comosum)

For best results, have at least one six-inch plant for every 100 square feet.


Peace Lily (Spathiphyllum sp.)

Other Benefits of Indoor Plants

Of course a home or office building cannot exactly mimic the controlled conditions of a research lab, but it is clear that having plenty of healthy houseplants leads to a healthier home. In addition to processing carbon dioxide and harmful chemicals, houseplants improve indoor air quality by:

  • Helping to maintain humidity levels: Dry indoor air is blamed for a host of respiratory problems, particularly in the winter, and plants emit water vapor during transpiration.
  • Producing negative ions: Plant leaves produce negative ions, similar to many air purifying machines. Negative ions attach themselves to (and effectively remove) particles such as dust, mold spores, bacteria, and allergens. The presence of negative ions is credited for increasing psychological health, productivity, and overall well-being.


A variegated form of English Ivy (Hedera helix)

The Other Side of the Debate

Some researchers, including the EPA Indoor Air Division, remain unconvinced that houseplants are the answer to cleaning indoor air. The reasons for their doubt include:

  • Houseplants should not be your only defense against indoor air pollution. Instead, pollution should be eliminated at its source by reducing the amount of synthetic material in your home or office, and by making sure buildings are well ventilated.
  • The average home or office building is different from a controlled research lab, so it’s difficult to determine if the results translate to the real world, or how many plants are needed to get the same effect. While no one disagrees that plants process chemicals in the air, their exact rates and effectiveness are hard to prove outside the lab setting. Some critics believe it might take hundreds of houseplants to get the same results as the NASA/ALCA study.
  • Too many plants can raise humidity levels too high, which could lead to mold and bacteria growth throughout the building. Indoor humidity levels should stay between 35%-65% to avoid turning your home into a “greenhouse.”
  • Moist soil breeds bacteria, mold, and mildew. Don’t overwater your plants, and help control mold by “mulching” your houseplants with a one-inch layer of fine gravel or other porous material.


Corn Plant (Dracaena fragrans ‘Massangeana’)

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16 Comments on “Best Houseplants to Improve Indoor Air Quality”

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  • DHC Comfort Says:
    July 21st, 2016 at 5:12 am

    Even the cleanest homes have air quality issues. Breathing particles such as bacteria, viruses, pollen, mold spores, dust mites and cigarette smoke can cause a large range of negative health outcomes. Research has shown that the indoor air quality (IAQ) can be many times worse than that of the outdoor air.



  • Paulo Says:
    October 15th, 2015 at 8:41 am

    Too bad only the Gerbera Daisy and Spider Plant are not toxic. Perhaps there’s a link between plant toxicity and ability to filter off-gases.



  • Alba Says:
    September 16th, 2014 at 8:39 pm

    This is an awesome TED Talk in wich the subject is the same adn this is the owner of the most healthiest building in delhi, very interesting! http://www.ted.com/talks/kamal_meattle_on_how_to_grow_your_own_fresh_air



  • MARIAN FRAIJO Says:
    July 31st, 2014 at 11:35 am

    HI MY NAME IS MARIAN AND I HAVE A HOUSE PLANT AND IT HAS LONG VINES I HAVE THEM HUNG ALL OVER MY WALLS. AND THE THING IS SOME OF THE LEAVES ARE TURNING LIKE THE ARE BURNED OR ARE DRYING OUT, CAN YOU PLEASE HELP ME WITH HOW I CAN SAVE THEM FROM DRYING OUT PLEASE? THANK YOU.



  • kat Says:
    July 27th, 2014 at 3:33 pm

    how long does it take after place oxygenating plants in ur bedroom to start noticing a difference. i have a couple snake plants i put in today… wonder how long will it be before i notice any difference.



  • Nina Says:
    June 23rd, 2014 at 3:09 pm

    I have a heart shaped philodendron that I purchased about a month ago. It seems to be thriving and has lots of new growth on it! However, the top of the soil keeps getting moldy?!?!?! I am not an experienced plant caregiver, but I do not water more than once a week(ish) if not longer. I have also tried re-potting and replacing the as much of the soil as I could but still the mold keeps coming back. Is this normal? Please help! It grosses me out to have mold growing in my plant but I love having the plant in the house! Any suggestions would be very much appreciated!



  • Jessica Says:
    November 14th, 2013 at 12:05 pm

    I have the houseplants that are at the top of the article that sent me here. I have an intense red orange mold growing in them, & I only water them about once a week letting the soil conpletely dry. I have recently noticed red seed looking things in the mold & they are ending up all over the house. We also have the scary black mold on most household surfaces I’ve been trying to clean. I’d like to know, should I scrape the mold out of my plant, & will it help with our allergies, etc. from the other not so forgiving molds. Can this mold spread a visible red spore that continues to grow on other surfaces?



  • yanggers Says:
    December 23rd, 2012 at 9:49 pm

    Rimal, and future readers,

    Many plants split up photosynthesis into two parts to conserve water: night time close most pores while stockpile CO2 in acid form, and day time open pores and finish the respiration to make sugar from CO2 + water. To read more search for CAM and C4 plants.



  • Nancy Wang Says:
    October 18th, 2012 at 8:32 am

    what house plants may be put in the bedrooms, where the lights are turned off during night?



  • jacqueline smith Says:
    June 30th, 2012 at 10:38 am

    Hi, I have many plants in my home, how large does a plant need to be to do the job in the home, for cleaning the air. I have small and large plants in the home.

    thanks, js



  • Rimal Says:
    August 20th, 2011 at 1:49 pm

    i would just like to know that how does a snake plant oxygen at night;although there is no sunlight….


  • Official Comment:


    Ben Erickson Says:
    February 22nd, 2011 at 5:31 pm

    Hi Grace,
    Your question about houseplants and VOCs has been answered by Julie Day on our website at Do Houseplants Release or Remove VOCs in the Air?. Thank you for your interest!



  • Grace Poblete Says:
    February 8th, 2011 at 9:47 pm

    I have read your article and read similar articles of the benefits of houseplants but I read few articles that these houseplants also produce VOCs, am confuse, just wondering which one is now true. Please, answer at once



  • amy Says:
    April 3rd, 2009 at 7:30 pm

    I live in a building basement and i have only 2 windows and my plants died very easy. Please tell me what can i do.


  • Official Comment:


    Julie Day Says:
    April 3rd, 2009 at 8:03 pm

    Amy, you may not have enough light for some houseplants. Try growing plants that tolerate low light, such as peace lily and pothos. Also, check out our Beginner’s Guide to Caring for Houseplants for tips on growing low-maintenance houseplants.



  • gloria Says:
    March 26th, 2009 at 7:22 am

    I would like to know what can I do with my corn plants leafs are spotted, spots are turning lighter, also leafs have brown spots? Please answer


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