Houseplants do so much more than just sit in a pot and look pretty. Some plants absorb harmful airborne chemicals. Today, we are going to learn more about NASA’s Clean Air Study, the houseplants that can cut your indoor pollution, exactly how these plants do that, and where you can get your own.
How Do Plants Purify Air?
During photosynthesis, plants absorb water, light, and carbon dioxide to make sugar and, in this process, oxygen is created as well. This is a benefit that plants have over air purifying systems, as even the most technologically advanced ones are not capable of creating oxygen.
Some plants are capable of producing oxygen even in low light conditions, and they are often the favorite of homeowners who don’t have that much sunlight inside their homes during the day.
According to studies carried out by NASA, Pennsylvania State University, the University of Georgia, and others, plants are capable of absorbing more than just carbon dioxide and can actually take in a variety of other gases. Among them are VOCs that are otherwise considered harmful, such as benzene or formaldehyde.
NASA’s Clean Air Study
Back in 1989, NASA published the results of a study that researched means to provide space stations with cleaner air. The NASA Clean Air Study was conducted together with the Associated Landscape Contractors of America (ALCA) and they discovered some very interesting facts about what plants can do for indoor air pollution.
The study showed out that plants can act against VOCs—an unexpected result. Just one plant per 100 square feet of indoor space is efficient in purifying the air. We will note that the research does have its limitations in home use; it was conducted in sealed, confined conditions mimicking a space station, so the efficiency of your indoor air purifying garden will likely vary according to your particular environment and the airflow through your home or office.
That said, a houseplant is always a nice addition to the decor, and if it helps clean the air, then why not have one or eight around the house? These are 10 of the plants tested in NASA’s Clean Air Study. Chances are, at least a few will be a good fit for your home or indoor space.
Best Air-Purifying Houseplants
English Ivy (Hedera helix), the creeping air-cleaner
English Ivy is a common air purifying plant but not a lot of people know that it has this “superpower.” It is often used as an outdoor ornamental plant for groundcover, planted walls, or privacy fences. It can be grown indoors, but it does truly thrive when planted outside. English Ivy is not fond of dry air—a common problem in most heated homes—and it doesn’t like air conditioning much, either. What the plant does love are humidity and cool nights. That’s why it’s recommended to mist your English Ivy, especially during winter.
The plant is a huge fan of bright light, but it should never be placed in direct sunlight during the summer. In winter, it does accept some sunlight so you can place it next to south-facing windows. As far as soil is concerned, English Ivy loves well-drained soil, but it still has to be moist. To grow ivy indoors, make sure you use a well-drained potting mix. Since it loves humidity, you shouldn’t let the plant’s soil dry out. If you provide the soil with even moisture, you are likely to see that beautiful red foliage in the fall.
In terms of fertilizer, know that English Ivy doesn’t require a lot of feeding. You just need to give it some fertilizer early in the spring and you should be good to go. When growth season is upon you, make sure that the plant gets controlled-release fertilizer. As for its air purifying capacity, English Ivy is good for cleansing toluene, xylene, formaldehyde, and benzene.
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Variegated gold, green and grey leaves. Aesthetically pleasing in every environment. Excellent vining effect and air-purifying, too!
Peace Lily (Spathiphyllum spp.), the elegant air purifier
The Peace Lily is one of the most beautiful flowering houseplants. It is a tropical plant that can bloom twice per year when cared for properly. According to NASA’s Clean Air Study, the Peace Lily is efficient is getting rid of airborne VOCs such as benzene, formaldehyde, and trichloroethylene.
Because of their exotic nature, these plants are only grown outdoor in the climate of Hawaii or Florida but make good houseplants pretty much everywhere else. They are shade-loving plants that don’t handle direct sunlight very well. When the plant is exposed to more light than it can handle, the leaves will curl and turn pale. The Peace Lily likes loose potting soil that’s rich in organic material. Since they love humidity, they will require plenty of watering and misting. When winter comes, you can water the plant less but make sure that the soil never dries out. The plants are fans of moisture and warmth, which is why they have to avoid cold drafts.
During the summer, the plants need weekly fertilizer. Alternatively, you can use slow-release pellets when the warm seasons approach. The plant needs no fertilizer during the winter. Note that unlike most other plants, the Peace Lily is toxic and should be kept away from children and pets. If you have a peace lily, check out our complete guide to peace lily care and troubleshooting.
Potted Live Peace Lily Plant
Purifies the air. Adds simple beauty and positive energy to a space. The more soil surface area, the better this plant is at capturing toxins and purifying the air; keep lower leaves trimmed.
Pothos (Epipremnum aureum), the easy-care clean-air powerhouse
Pothos goes by many different names: silver vine, devil’s ivy, devil’s vine. It is one of the easiest houseplants to grow and a very popular one among beginners. Studies have shown that pothos of all varieties can be efficient in getting rid of indoor pollutants such as formaldehyde, xylene, and trichloroethylene.
When grown indoors, the plant prefers bright but indirect sunlight. If you notice that the leaves are getting pale out of nowhere, that means the plant is exposed to too much light. On the other hand, if the leaves lose their pattern, they might be experiencing a lack of light.
As for the soil, the plants love well-draining potting soil. Good news for people who often forget to water their plants: the pothos prefers it when the soil is completely dry before watering. In fact, if you provide the plant with moist soil all the time, chances are the roots will rot. When this happens, you will notice black spots on the leaves. While the plant does love high humidity, it should be able to grow just fine even when humidity levels are low.
Since they are not hungry plants, you don’t need to invest too much money in fertilizer. If you feed it houseplant fertilizer about two times per month, that should be enough.
Also important to note: the Devil’s Ivy is a toxic plant when ingested. If you have pets, you want to keep them as far away from the plant as possible. The plant contains calcium oxalate crystals, so if your pets ingest it, they can end up with mouth irritations and end up being poisoned.
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Fun, easy collection of three varieties of pothos. Each is unique in their leaf coloring and variegation. Easy to care for: adapt easily to low light and occasional lack of water. Pothos trail and spill over their pots—a great option for a stand or shelf that can showcase their long vines.
Weeping Fig (Ficus benjamina), the VOC-scrubbing tree
The weeping fig has found its way into households all over the world, thanks to its
easy care and attractive shape. As for its air-cleansing capabilities, the weeping fig is known to efficiently remove air traces of toluene, xylene, and formaldehyde.
If you want to grow a weeping fig at home, you will need to provide it with plenty of bright indirect sunlight. It also wouldn’t hurt if it gets some direct sunlight exposure in the morning when the rays aren’t that powerful. One important thing to note about the weeping fig is that it doesn’t like being moved around too much (its leaves can drop when this happens), so it is best if you find a good spot for it and try to leave it there.
When it comes to soil, a weeping fig will do just fine with fast-draining potting soil. They aren’t pretentious when it comes to organic matter and they don’t need soil that’s very rich in nutrients. For repotting, it’s best if you use potting soil with vermiculite, sand, or perlite. You want to keep the plant moist but not in soaking soil, otherwise, it can develop root rot and the leaves will start to fall.
When caring for the weeping fig, moisture levels need to be stable because the plant normally sheds leaves when the dry season starts. Since they are tropical plants, weeping figs need constantly high humidity levels. You should try to keep the soil moist but consider having a humidifier that can keep humidity constant.
Unlike other plants that are low maintenance, the weeping fig likes to feed a lot, so you will have to fertilize it constantly during the growing season. In case you notice that your plant has all the right conditions to thrive but its leaves are still dropping, you can consider adding some manganese and magnesium to the soil.
Spider Plant (Chlorophytum elatum), the classic air purifying plant
According to the very same NASA study, the spider plant has proven to be efficient in clearing the air of toluene, xylene, and formaldehyde, but the reason why a lot of people buy it is because it’s very easy to care for.
As creepy as the name may sound at first, the spider plant is anything but a creepy plant. It has beautiful green foliage that looks almost like a fireworks explosion. They aren’t at all demanding when it comes to light. While they do thrive in bright light, they do not like being in direct sunlight, as this causes the plant to scorch. They can, however, tolerate partial shade without any problems.
During the summer, they like liberal watering and occasional misting. When the cold season approaches, you won’t have to water the plant often. As for the soil, spider plants are fans of well-aerated potting mix. In the summer, you want to feed your spider plants with a liquid fertilizer every week. Alternatively, you can use pellets when the growing season begins.
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Brilliant foliage makes a striking accent. Small plantlets and white flower sprays. Perfect for hanging baskets or planters. In the garden, it trails as a seasonal ground cover. Ships in a 10-inch hanging grower's pot. Most have multiple spider plantlets at the time of shipping.
Parlor palm (Chamaedorea elegans), the low-light air cleaner
Native to the rainforests of Guatemala and Southern Mexico, the parlor palm plant has leaves that are so bright and beautiful, they are often used as part of floral bouquets and arrangements. People also use them to make wreaths, as the plant can survive up to 40 days after being cut. What’s more, the parlor palm is one of the few plants in our list that’s efficient in absorbing all VOCs that were part of the study: xylene, toluene, trichloroethylene, benzene, and formaldehyde.
Because they can thrive in low light conditions, these palms can be placed in spots where they can enjoy bright light whilst avoiding direct sunlight exposure. When you grow this plant indoors, you can use a high-quality potting mix (just make sure that the mixture doesn’t break down). Be careful, as it will not tolerate salty soil.
What you absolutely want to avoid when growing this plant is overwatering. If the soil becomes saturated, there are chances the plant will suffer, so add water whenever the first inch of soil has dried out.
The parlous palm prefers moderate humidity levels. In case you start to notice brown tips or dry leaf edges, that means that there is a cold draft that the plant can’t stand, so figure out how to raise the humidity levels. You can use weak liquid fertilizer applied a maximum of two times during the growing season. The palm doesn’t need any fertilizer during the winter.
Small Parlor Palm in Custom Planter
Can grow to six feet tall. Produces inedible fruit from flowers at the base of the plant. Usually will not flower indoors. Prized for its resilience to indoor conditions and reliable habit.
Chinese evergreen (Aglaonema modestum), the flashy pollution-buster
According to the same NASA study, it seems like the famous Chinese evergreen plant has some air-purifying capabilities as well. Studies have revealed the fact that the plant can absorb pollutants such as benzene and formaldehyde. But what does it take to care for this plant, should you decide you want one?
Oddly enough, there is one rule that will help guide you toward proper Chinese evergreen care: the lighter the variety you own, the more light it requires. For instance, if you have a variety of Chinese evergreen that’s in a dark green shade, which means it can thrive in shady areas. While plants that are lighter in color also need more light, try to avoid placing the Chinese evergreen in direct sunlight.
As for the soil, this plant thrives in well-drained and slightly acidic potting soil. During the summer, it will require frequent watering, but you might also have to apply mist if the air is too dry, as the plant loves humidity. For the most part, the Chinese evergreen plant will grow successfully when it has greenhouse-like conditions: humidity, warmth, and plenty of light.
If you’re not sure what type of fertilizer to use, know that this plant loves liquid fertilizer during the growing season, but you can also get away with slow-release pellets.
Florist’s chrysanthemum (Chrysanthemum morifolium), the short-lived all-star
Yes, the beautiful chrysanthemum is yet another plant that you probably didn’t know has air purifying capacities. As NASA’s study shows us, the plant is able to remove benzene, xylene, toluene, formaldehyde, ammonia, and trichloroethylene from the air inside your home.
The tricky thing about growing these plants is that the rules of care will depend on the exact variety that you’re trying to grow and the exact climate where you live, so we’re going to try and give you some general tips that work for most varieties. First of all, there’s the light issue. While you want the plant to be able to enjoy as much bright light during the day as possible, at night, it’s best if you remove it from any spots where artificial light can reach it, as this will throw off the plant’s bloom production.
It is important that you water the plant on a regular basis, making sure that water doesn’t touch the leaves so there will be no fungal issues. It’s also important to note that the plant doesn’t really like high levels of humidity either.
We’re sorry to inform you that indoor-grown chrysanthemums won’t live very long. They usually flower for three to four weeks and that’s about it. That’s because it’s difficult to make these flowers rebloom in indoor conditions, and trying to replicate their outdoor needs is way too complicated. For this particular reason, a lot of people turn chrysanthemums into compost once they’ve died.
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Aloe Vera (Aloe barbadensis), the multitasking kitchen plant
Aloe Vera is a plant that doesn’t really need an introduction. Almost everyone knows the wide variety of uses that Aloe Vera has in the pharmaceutical, cosmetics, skincare, and even food industry (since there are lots of brands that now sell vitamin water infused with Aloe Vera). And if that wasn’t enough, NASA also taught us that this miracle plant can remove benzene and formaldehyde from the air, as well.
What’s even more surprising is that Aloe Vera is a plant that’s not at all complicated to grow indoors. It requires very little and gives back so much. When inside, the plant needs bright light but note that sunlight exposure can cause the leaves to burn. Soil needs to be well-drained to mimic its natural habitat. Cactus potting soil should work just fine.
As for water, Aloe Vera is very resistant to drought, but you can water it regularly to help it thrive. It’s best if you leave the soil to dry out completely between two waterings. If you notice that the leaves are shriveling, then the plant has been left in dry soil for too long. The plant will recover once watered but this puts it under a lot of stress which is not recommended (as the plant will eventually die).
It doesn’t even need too much fertilizer. You can add fertilizer once every spring (pretty much any houseplant fertilizer will suffice). If you want even more Aloe Vera-related good news, know that the plant is also very resistant to pests and diseases, with the most common problem being root rot from overwatering.
Alluring Aloe Collection
Revered for their medicinal power and hardy nature. These 4-inch pots are perfectly sized for a bookshelf or kitchen counter. Comes with three aloe vera plants fully rooted in 4-inch round pots. All orders come with detailed care instructions.
Barberton Daisy (Gerbera jamesonii), the air purifier that flowers
Daisies are plants that we’ve come to love a lot throughout the decades, but who knew that one of the most common flowers on the planet is actually capable of absorbing air pollutants such as formaldehyde or benzene?
When it comes to growing your own daisies, know that the plant is a little more pretentious compared to others one we’ve added to the list. The plant loves full sun to partial shade but you have to avoid placing it in spots with intense heat. This will, of course, depend on the climate where you live. Those of you living in warmer areas should allow the plant to bask in the morning sun, while those who live in colder regions can afford to leave the plant in full sun throughout the day.
As far as watering is concerned, the Barberton daisy needs about one inch of watering every week but only when you notice that the surface of the soil is dry. Make sure that you avoid watering during the winter, when the plant goes dormant. If you’re curious about what type of fertilizer this plant needs, know that it depends on the amount of soil in question. If you want the plant to bloom the entire summer, you want to add water-soluble fertilizer once per month.
How many of you knew that some of the most common household plants are actually efficient in absorbing harmful air pollutants that one could find inside their home? It’s true that the level of efficiency for this type of absorption is quite controversial, and there are many articles that claim that the reduction provided is insignificant to make a difference, NASA has always provided us with trustworthy information. Worst case scenario, you end up having a house full of beautiful plants that produce oxygen. It’s a win either way.