Seven Plants That Will Improve the Air Quality in Your Apartment
Among the many reasons to keep plenty of plants in your home: They are incredibly effective natural air filters. How do they do this? And exactly what do they remove?
Read on to learn a bit of science behind this phenomenon, and then consult the list to choose the most helpful plants for purifying your indoor air.
Plants have small pores on the underside of their leaves (and sometimes the stem) called stomata. Stomata handle the respiratory function of your plant. More specifically, carbon dioxide enters through the stomata and oxygen and water vapor exit through them. Think of the stomata like a bunch of tiny mouths—the more stomata, the deeper your plant “breathes.” These small mouths open and close to allow for the gas exchange and to limit the loss of water from evaporation. Most plants’ stomata are open during the day, when photosynthesis occurs, and closed at night. However, some plants open their stomata at night because it’s crucial they retain water in traditionally dry environments.
The first list of air-filtering plants was compiled by NASA as part of a 1989 clean air study that researched ways to clean the air inside space stations. Working with the Associated Landscape Contractors of America, the list they compiled is very specific, and the study states that at least one medium-large plant per 100 square feet is needed in the home or office. The results also show that certain common indoor plants may provide a natural way of removing toxic agents such as benzene, formaldehyde, and trichloroethylene from the air, helping neutralize the effects of sick building syndrome.
Benzene, a known carcinogen, forms naturally from combustion (such as volcanoes and forest fires). Most human exposure to benzene is from manufacturing, motor vehicle exhaust, and cigarette smoke.
Formaldehyde is another air pollutant and carcinogen. A byproduct of combustion, it can occur naturally, but usually doesn’t inside a city. Indoor levels are usually much higher since it’s found in treated wood and manufactured wood products (such as particleboard, plywood, and fiberboard). It’s also found in cigarette smoke, some fabrics, and insulation material.
Collectively referred to as volatile organic compounds (VOCs), ammonia, xylene, toluene, and trichloroethylene are known carcinogens commonly found in homes. They can be released by a wide variety of paints and inks, household cleaners, and glue, just to name a few.
The good news is that houseplants can help. The seven plants below were found to be the most effective at removing toxins. Interestingly, plant and potting soil filtering performance improves as potted plants adapt to higher pollution levels.
It’s worth noting that all leafy plants must be regularly dusted to protect people with asthma and allergies. A HEPA filter can provide additional benefits, but including some of these plants in your place can improve your air quality and turn your place into an urban oasis. The improvement is noticeable, and a little extra humidity from a lush home can even improve sleep.
Peace-Lily (Spathiphyllum wallisi ‘Mauna Loa’)
Peace-lily was found to be the best for cleaning the air, hands down. It’s great for removing all the aforementioned chemicals from the air—and it is very easy to care for. While the peace-lily is not pet-friendly, it is definitely people-friendly—just provide a shady spot and water as the soil turns dry (it also handles bright, filtered light). The white blooms last for about two months and it can bloom in spring and fall.
Mother-in-Law’s Tongue, or Snake Plant (Sansevieria trifasciata ‘Laurentii’)
A close second-best cleaner is the snake plant (it does not remove ammonia). It survives neglect and a variety of light and humidity conditions, and it opens its stomata at night while you are sleeping, which makes it an ideal bedroom plant. Sansevieria trifasciata “Laurentii” was the specific variety in NASA’s study but all sansevieria clean the air quite well so feel free to include others for variety. It works very fast and is easy to clean with a damp cloth, making it a friend to those with allergies and asthma. As this succulent is a part of the lily family, it is also toxic to cats and dogs.
Creeping Lilyturf (Liriope spicata)
Our third best air-cleaning houseplant is chosen based on efficiency, hardiness, light flexibility, and for being nontoxic to pets—lilyturf. Also known as monkey grass, this plant is adept at removing formaldehyde, ammonia, xylene, and toluene from the air, and can be used in a variety of ways indoor and out. It’s a thirsty subtropical plant so it requires regular watering and part shade to part sun, but quickly recovers from a little neglect. Despite the name, this grasslike perennial is not a lily, and blooms in late summer with small white to lavender flowers.
Dragon Tree (Dracaena marginata)
Our fourth houseplant is a broad-leaf evergreen—the dragon tree! This plant comes in several cultivars, ranging from green with red edges to bright pink with thin green streaks. Larger versions can be used as to create the illusion of height in a room. While dragon tree removes benzene, formaldehyde, trichloroethylene, xylene, and toluene from the air, it does not remove ammonia, and it is considered toxic to pets. It prefers to be watered when the soil is mostly dry and loves lots of indirect light. There are over 120 dracaena species so be sure to choose the Dracaena marginata species or the ‘Janet Craig’ cultivar for the best air filtering. Still, most species will clean the air to some degree.
Gerber Daisy (Gerbera jamesonii)
Some will wonder, isn’t a Gerber daisy an outdoor plant? No, not exactly. This plant can live perfectly fine indoors with little fuss, and has a lifespan of about three years once acclimated. It needs bright light but does not like the heat—it thrives at room temperature (or a little lower). A pet-friendly plant, the Gerber daisy is adored for its lovely blooms, but once it stops blooming the remaining plant and foliage still make an excellent air purifier by removing benzene, formaldehyde, and trichloroethylene. In fact, it removes significantly greater amounts of benzene than any other plant tested. Gerber daisy likes monthly fertilizing, and with a little deadheading it will produce a lot of beautiful flowers in the warmer months.
English ivy (Hedera helix)
Also thought of as an outdoor plant, English ivy makes a wonderful houseplant and air purifier. Besides removing benzene, formaldehyde, trichloroethylene, xylene, and toluene, English ivy was also found to remove a whopping 78 percent of airborne mold and fecal particles over 12 hours by the American College of Allergy, Asthma & Immunology.
Before you bring this marvelous plant in your home there are a couple of things you should know: It is poisonous to pets and humans, and sensitive people can acquire a rash simply from touching it. Although it’s a relatively easy houseplant, it requires bright light, good drainage, and infrequent watering to stay happy. A bright bathroom or bedroom is a great spot for keeping Hedera helix but be sure to regularly trim before it anchors to the wall. Despite the necessary precautions, it is definitely a plant worthy of this list.
Boston Fern (Nephrolepis exaltata)
Our last houseplant is far from the least worthy. While this classic houseplant only removes formaldehyde, xylene, and toluene, it is large, airy and showy, and also pet-friendly. It loves bright indirect light and can thrive in any humid location. For this reason, many people hang Boston ferns in well-lit bathrooms or set them on trays of wet pebbles. If you remember to water this showstopper, it will provide years of beautiful serenity as well as fresh air.
Michelle Inciarrano will teach Houseplants 101 December 2.