You didn’t read that title wrong my friends. There few things that get Miss Pot Plant as hot under the collar as scientific research which supports the role of plants for improved health and wellbeing. Amazeballs.

So, the big question: can houseplants actually purify the air, and if so – which plants are the best for cleaning your air at home?

According to NASA, yes! The NASA clean air study found numerous common house plants which release oxygen into the air through photosynthesis, as well as absorb carbon dioxide and a variety of other toxins  from the air. The top performers identified in the study included;

  1. Peace Lily (removes 5 toxins from the air)
  2. Florists Chrysanthemum (removes 5 toxins from the air)
  3. Red-edged Dracaena (removes 4 toxins from the air)
  4. Variegated Snake Plant (removes 4 toxins form the air)
  5. English Ivy (removes 4 toxins from the air)

We find this very exciting. There are way too many “plants will magic away your worst diseases and turn your air into the nectar of the gods” type blog posts out there which make grand claims based on nothing more than fellow bloggers, Pinterest posts and the like.

 Now of course, science doesn’t know everything, but if you’re going to tell someone to buy a plant because it will do “a” or “b” – I feel like you should be able to show that there’s at least SOME evidence behind your claims. But maybe that’s just me.

We at Miss Pot Plant believe firmly in providing you with reputable and researched information where available (we’re probably not going to do a literature review for a DIY project though). We’ll also tell you when our recommendations are based on runes and star trajectories.  

With this in mind, in this article we will;

  • Review NASA’s research into the use of plants to purify air 
  • Examine the relevance of this for the home enviornment 
  • Identify the 5 plants which were the “super performers” according to NASAs research – and provide growing tips for each

Sounds good? Let’s dive in.

P.S if you have 0 interest in “why” or “how” plants might clean your air, skip to the end where I cover the plants NASA recommend as super purifiers. I will hold it against you though.

Why did NASA study plants?

 

NASA conducted the clean air study in 1989 in order to determine the ability of plants to clean up recycled air in space stations.

Why did they study this you ask? Because astronauts are forced to breathe the exact same air over and over for the period of their expeditions in space (apparently fresh space air isn’t a winner).

 The problem with breathing recycled air as that eventually toxins and carbon dioxide (expelled as waste when we exhale) accumulate in the recycled air, making the air progressively less fresh and potentially toxic. Not ideal really.   

 Thus, NASA were keen on findings ways to purify recycled air in space. The Clean Air Study was part of this search.

 Numerous common houseplants were examined for their ability to add oxygen to the, remove carbon dioxide (which we breathe out) and other toxins such as benzene, formaldehyde and trichloroethylene (not good for you Janice) from the air.

 Some plants were able to add oxygen, remove CO2 AND remove all the tested toxins from the air, while other plants were only able to manage some of these. We’ll cover the stand out performers soon.

Does the NASA study really apply to your house plants?

The answer is yes and no. Yes, NASA clearly demonstrated that numerous plants can remove chemicals and toxins from the air, and add oxygen. Yay!

However, this study does not establish whether this process is the same, more efficient, or less efficient in the home environment. Stay with me here Janice. Impressive dinner conversation lies ahead. 

NASA found one plant per 9m2(100 square feet) was sufficient for air cleaning effect – but we don’t know from this study whether this is true of our homes either. 

The study was conducted in a sealed space station; not your house. 

Overall, we think the results are exciting – the idea of cleaning our home air by virtue of beautiful plants is pretty darn awesome.  

But we’d like to review the modern literature thoroughly to see if we can verify NASA’s findings. We are doing this currently and will share the results with you soon!

Don’t be dissuaded by this though – remember, there is NO downside to filling your home with these beautiful air cleaning purifying green machines;  Even if (at the very worst), they don’t clean your air quite as well as space station air, they’re still beautiful!

How did NASA rank a house plants ability to clean air?

The study tested the ability of a house plant to;

  1. Produce new oxygen, released into the surrounding air as a by-product of photosynthesis
  2. Absorb carbon dioxide from the surrounding air, as food for photosynthesis
  3. Absorb harmful chemicals for the surrounding air, specifically the following
    1. Benzene
    2. Formaldehyde
    3. Trichloroethylene
    4. Xylene and Toulene
    5. Ammonia

They also determined the quantity of oxygen produced, and quantity of toxin removed. Nerds. 

The plants which showed the most pronounced ability to accomplish these tasks were considered to be of most use for purifying air. We’ve selected the top 5 – see below!

The 5 best air purifying houseplants according to NASA

 And the winners are; 

 

1. The Peace Lilly (spathiphyllum)

 

Beauty and style meets function. Who knew. The beautiful peace lilly is a happy camper indoors and isn’t too hard to grow, and it’s a machine at cleaning your air.

The peace lilly adds oxygen to your air, and it removes 5 toxins from the air (that we know of) – including benzene, formaldehyde, trichloroethylene, toluene and ammonia. What a gun.

 

Grow tips for the Peace Lilly

Light requirements: Moderate to bright indirect sunlight. Eastern windows work well.

Watering: Filtered water, generously when plant begins to droop.

Styling: Great table plant, though can work as a feature plant. Also useful in bathrooms and bedrooms – doesn’t mind lower light conditions and deals well with humidity. White flower are gorgeous.

Fertilise: 2-3 times a year during the warm seasons. Use a dedicated or balanced fertiliser. Doesn’t require much.

Pests: Generally quite resistant. Can get spider mites. aphids and mealybugs and scale – but not usually.

Propagation: Divide mature plants and repot.

Other comments: One of the most tolerant and easy to grow houseplants.

 

2. Florists Chrysanthemum (chrysanthemum morifolium)

 

Chrysanthemum is derived from the Greek work chryos, meaning gold. and anthemom, meaning flower – and no wonder. This “golden flower” isn’t just big and beautiful; she’s a air purification station and you ought to get one in your house ASAP Janice.

The Florist Chrysanthemum removes 5 toxins from the air as well as pumping out sweet fresh oxygen and absorbing CO2. Golden alright.

Florist Chrysanthemum care tips

Light requirements: Prefers bright light, and usually won’t flower without it. No direct sun though – keep it indirect.

Watering: Likes to be moist around the clock. Water when top 0.5-1cm of soil had dried.

Styling: The easiest solution to add some plant colour to a room.

Fertilise: Don’t.

Pests: Usually not an issue.

Propagation: Not usually worthwhile for the indoor chrysanthemums.

Other comments: Cheap and easy to find, we plant these indoors over the summer for 6-8 weeks (whilst blooming). After this, we compost them. Cruel I know. Like raising a pig for slaughter. But they won’t usually bloom again and its not worth the hassle of keeping them alive over winter. Compost and buy some cheap ones again next season.

 

3. Red edged Dracaena (Dracaena Marginata)

One of the most rugged and care free indoor plants going around. The Dracaena will survive almost anything, and still remove 4 nasty toxins from your home at the same time. All hail our red master.

Care tips for the red edged Dracaena

Light requirements: Medium indirect light. Will usually tolerate bright indirect light also

Watering: Water when top layer of soil (5mm-1cm) dries. Do not overwater 

Styling: Looks great as a feature floor plant by furniture or in a corner. If you have smaller one’s they make nice table plants until they get too big. If you’ve a big pot, plant several and cut the cane’s at different heights as they grow – creates a nice multilevel effect

Pests: Spider mites and occasionally mealybugs

Fertilise: Warmer months: every 2-3 weeks. Winter: every 6 weeks

Propagation: When the plant has reached your desired height, cut the cane at any level you wish. You can then cut the left over cane into 10-15cm lengths and plant like normal stem cuttings.

Other tips: Low maintenance plant! Repot every 1.5-2 years. If leaves are browning is probably getting too much sun. Yellow leaves normally indicate root rot from overwatering or poor drainage.

 

4. English Ivy

 

I personally think the english Ivy is one of the most regal and stunning plants you can add to your home. Maybe I’m just posh. But it’s not all look and no action: the english ivy removes 4 toxins from your home, and gives you style cred for free. 

Care tips for the engligh ivy 

Light requirements: Medium indirect light. In winter may need bright indirect light, depending on climate and length of light exposure.

Watering: Water only when top 1-2cm of soil is dry.

Styling: The perfect trailing, hanging or cascading plant. Looks awesome on bookshelves, mantles, window sills, hangers, bed frames, balconies etc.

Pests: Spider mites, scale, mealybugs
Fertilise: Monthly year round – high nitrogen fertilisers work well

Propagation: Cuttings can be stripped of lower leaves and stems placed in water until root balls form

Other tips: If a variegated variety becomes solid green, it’s not getting enough light. Move, or use additional fluorescent light as a top up. Plant will suffer if overwatered – make sure ivy is planted in well draining soil and not overwatered.

 

5. Variegated snake plant (sansevieria)

 

Are you even an indoor gardener if you don’t have a cheeky snake plant lurking somewhere? Super stylish and super easy to grow – bet you didn’t know it was cleaning your room air as well. Removes 4 toxins. Legend. 

 

Variegated snake plant care tips

Light requirements: Medium indirect light. They’ll tolerate low light as well. And bright light. So yeah like whatever light you want?

Watering: Don’t go too heavy with the water. Let it dry up before watering again; somewhere between 2-4 weeks between waterings.

Styling: These plants have modern and hard edges, which make them great for adding shape or modern styling to a room. Good both on benches and as feature plants besides tables, coffee stands, tv cabinets, bookcases.

Fertilise: If you can remember, maybe once or twice during spring. Not sure if the snake plant cares.

Pests: Highly resistant. Mealybugs or spider mites in some cases.

Comments: Almost impossible to kill.

  

Summary

And so, the question of whether plants can actually clean our air may have been answered thanks to NASA – but Miss Pot Plant is not satisfied with one study 30 years ago. We are currently conducting a literature search and will report back faithfully.

In the meantime, these 5 plants identified by NASA as being air purifyinng machines are a good start for those wanting to freshen their indoor space. For other good performers that didn’t make the top 5, see https://ntrs.nasa.gov/search.jsp?ref=organicgglunkwn&prid=pfseogglunkwn&R=19930072988

Much love 

Miss Pot Plant xoxo