The 18 best air-cleaning plants, according to NASA

The best plants are the ones that do double duty – and all of these purify your air of toxic chemicals. Even better, they’re easy to grow.

Natural purifiers in a pot
The best plants are the ones that do double duty – and all of these purify your air of toxic chemicals. Even better, they’re easy to grow. According to the Environmental Protection Agency, our homes can have three to five times more pollutants than the outdoors. You could be living in a “sick” house and not realise it: Substances like xylene (in paint and lacquers), benzene (furniture wax, insect sprays), trichloroethylene (cleaners, adhesives), and formaldehyde (upholstery, air fresheners) – can produce symptoms like headaches, sore throats, or allergy-like breathing troubles. The NASA Clean Air Study was designed to find effective and simple ways to detox the air in the space station – and it reveals that common house plants have air purifying superpowers.

Dwarf date palm
It’s hardy and drought-resistant, but it’s a slow grower. Once this palm matures, it will live for decades and grow 2.5-3 metres tall with sharp needle-like spines arranged near the base of the leaf stem – take care around them, they can penetrate through skin and clothing. However, the dwarf date palm is noted for its ability to filter out xylene. For optimal air-filtering, NASA recommends placing at least one plant per 9 square metres of a home or office space. Check out these 10 houseplants that are nearly impossible to kill. 

Boston fern
Boston ferns are native to tropical forests and swamp areas so they will thrive in low light and high humidity – they’re ideal for your bathroom. The moisture from your shower will hydrate the plant, requiring little extra care from you. Besides being a pretty and decorative addition to your bathroom, the Boston fern helps remove xylene and – the NASA study revealed – it was the top house plant for removing formaldehyde. Find out 7 other ways to improve the air quality in your home.

Kimberly Queen fern
Another fern makes the NASA list: Unlike the Boston fern, which spreads out towards the side, the Kimberly Queen grows upright, giving it a tidy appearance. This Australian native can take more heat and sun than its Boston cousin, but you do have to water it on a regular basis. Since it can grow indoors or out, this fern makes an attractive addition placed under an overhang on a patio or deck, especially if it’s an area in close quarters to a garage or as xylene agents are in vehicle exhaust. Follow these 7 tips to keep plants alive when you're away.

Spider plant
Talk about a plant that keeps giving. It removes impurities from the air like formaldehyde and carbon monoxide. NASA’s study found that spider plants removed 95 per cent of formaldehyde from a sealed plexiglass chamber in 24 hours. Even better, the main plant sends out shoots, called “spiderettes” that flower and eventually grow into baby spider plants that you can transplant. That also helps: Research indicates that people are more relaxed and happy after caring for plants – say, for example, when they’re re-potting them.

Chinese evergreen
A sturdy plant that’s easy to keep alive, this one is ideal for your desk or on a living room side table. Its lance-shaped leaves are interspersed with pretty shades of grey, green and silver. It thrives in low to medium light and is slow-growing – it lives to a ripe old age of 10 years. The evergreen plant filters formaldehyde and benzene. Just take care if you have pets or young ones: It’s toxic when ingested. Always consult the ASPCA list of poisonous plants for cats and dogs before buying a plant, including the ones included in the NASA list.

Bamboo palm
This plant boasts elegance and height in addition to removing harmful elements like benzene and formaldehyde. Bamboo palms also help keep indoor air moist, making it a welcome addition in dry winter months. This palm takes a bit more care: It loves bright, but not direct sunlight and needs monthly fertilising and regular misting; when it outgrows its container (every two to three years), you’ll need to re-pot it.

Weeping fig
According to NASA’s Clean Air Study, the weeping fig is very efficient at cleansing airborne formaldehyde, xylene and toluene. Xylene and toluene tend to build up from carpet and furniture cleaners and stain removers. This one is easy to care for, so you can place a couple in each room. Just keep them out of direct sunlight and they’ll be a companion for decades.

Devil’s ivy
Devil’s ivy is actually quite angelic. It’s considered one of the most effective indoor air purifiers from benzene, formaldehyde, and xylene. Plus, if you’re new to growing house plants, this is a great first plant to get. It’s lush, hardy and inexpensive. Another nice feature is that it can grow up to 2.5 metres long and in a variety of directions. In a hanging basket, it will trail downwards. Place it a pot and train it to climb a totem or trellis or place in a pot on a mantle or coffee table and let it grow horizontally.

Flamingo lily
A beautiful pop of colour and an air filter to boot, this showy evergreen plant is known for its shiny, heart-shaped red flowers. According to NASA, it removes airborne formaldehyde, ammonia, toluene and xylene. Take note – this one is toxic, so avoid it if you have pets or kids. Speaking of pets, here are 5 easy ways to make your garden a great home for your pets. 

Lilyturf
This popular ground cover has grassy leaves that are spiked, and it produces blue or white flowers. Although it is usually grown outdoors, it does very well as a window sill plant and since it helps remove trichloroethylene (in printer ink and dry cleaning chemicals), xylene (permanent markers, colouring pens, print cartridges) and ammonia (common aerosols), you may want to line your office or home office windows with pots of lilyturf.

Broadleaf lady palm
You’ve probably seen this in shopping malls, offices and hotel lobbies because they tolerate low levels of light. With a maximum height of around 1.8 metres, they are perfect as a stately and dramatic feature for the low sunlight corners of your home. They do need regular watering and moist soil, but you’ll benefit from the plant’s ability to cleanse the air of formaldehyde, ammonia, xylene and toluene.

Gerbera
These colourful and cheerful daisies were mainly outdoor plants until florists started using them in arrangements. Grown indoors, they can produce flowers at any time of the year, in white, red, orange, pink and purple. The flowers usually last around four to six weeks, but even without the flowers, the gerbera or Barberton daisy has lush, dark green leaves that are effective at filtering out formaldehyde, benzene, and trichloroethylene. They are most happy with full sun and plenty of water and well-drained soil.

Cornstalk dracaena
You’ll be tempted to look for an ear of corn within the leaves of this plant because it really looks like a corn stalk in a pot. It doesn’t yield sweet corn but it does help rid your home of toxic agents like formaldehyde, trichloroethylene, and benzene. The plant doesn’t require too much – it can handle low light and the occasional missed watering. Find out which gardening tips you should best ignore here.

English ivy
If you work in a salon or do at-home salon treatments with keratin, hair colouring, perms, hair-straightening, nail polish, or nail polish hardeners, consider placing some English ivy in the room. It filters out four toxic agents – trichloroethylene, formaldehyde, benzene, and xylene, which are found in these salon products. A hardy plant that can tolerate low light in intermittent watering, it looks lovely in a hanging basket with vines trailing over the side.

Variegated snake plant
Because this plant needs humidity, it’s perfect for your bathroom – the right place for it to filter out the formaldehyde in cleaning products, facial tissues, toilet paper and hair treatments and dyes. If you remember to mist it, the snake plant is also a nice addition to your bedroom because it gives off oxygen at night – a sleeping aid. Find out which other plants are perfect for keeping in your bathroom. 

Red-edged dracaena
For people planning home improvements, start by investing in some red-edged dracaena plants. It is rated as one of the best plants for removing trichloroethylene, found in some home improvement materials such as paint removers and strippers, adhesives, varnish remover and aerosol degreasers. Conveniently, these plants are sold at home improvement stores. They’re easy to grow and maintain and will reach about three metres tall with a spread of one metre; they live for decades under the right care.

Peace lily
The hidden talent behind the lush and beautiful peace lily is its excellent air filtering system. It boasts a high transpiration rate – that means it carries a lot of water from the roots to the leaves and releases moisture back into the room. Another benefit: Peace lilies soak up mould spores. If you want to encourage pretty flowers, keep it in a spot that gets morning – but not afternoon – light and make sure to mist the leaves and keep the soil damp.

Florist’s chrysanthemum
While technically not a houseplant, these bright, colourful blossoms are usually abundant in stores in autumn. Be sure to bring some indoors: They knock down levels of all the harmful pollutants NASA studied. Decorate for autumn and place mums anywhere in your home where they can get not-too-warm bright sunlight. Water them often and deadhead the flowers to keep the plant looking healthy, and you’ll be able to enjoy blooms for six to eight weeks.

This article appeared on Reader's Digest.