Associated Group Big enough. Small enough.

I’ve had many reactions to my last blog about healthifying your home or workplace.  Most of them asking for more specifics about how houseplants positively affect our indoor environments and a few wondering if I would make up some new words for them.  One even commented that “caring for plants is great but what do I get out of it?”

Well actually the fact is, you get quite a lot.  For the cost of some water, light, fertilizer, and a little attention, indoor plants can contribute quite a number of quite important benefits to those people living in their midst.  Yes, indoor plants wear many different hats – Oxygen Producer, Carbon Dioxide Reducer, Air Humidifier, Volatile Organic Vapor Destroyer, Noise Suppressor, Stress Reliever, Mood Enhancer, and all-purpose Room Beautifier.  You can even hang them on your wall as artwork (see my previous blog Got Green Walls?).

Plants are all that and more, so as promised, let me elaborate a little on some specific varieties and all the jobs they do for us.

1. Oxygen Producer – Happily for us and all the other animals on this planet, all green plants perform a process known as Photosynthesis, in which Carbon Dioxide from the atmosphere is metabolized into Oxygen.  Most plants do this activity all day long and into the night if you leave the lights on and a few release their Oxygen more so after night fall such as Succulents, Bromeliads, and Orchids.  Every plant species differs some in their comparative rates of Oxygen released, but one rule seems to be true – the more leaf surfaces exposed to light, the more Photosynthesis occurs (and more Oxygen is produced).  With that in mind, it would be best to use plants with very large leaves or with many, many small leaves.  How many plants should you use?  Well that depends on the size of the room and the number of people in it.  According to the TED Talk by Kamal Meattle, incredibly a person could be placed in an airtight chamber with four 6 foot Areca Palms (Dypsis lutescens), eight 3 foot Mother In Law’s Tongue (Sansevieria trifasciata), and an equivalent number of Golden Pothos (Epiprenum aureum) and have sufficient Oxygen to survive indefinitely!
2. Carbon Dioxide Reducer – As many are aware, Carbon Dioxide has been reported in the news lately as being the primary cause of Global Climate Change.  With levels of this gas rising in the earth’s atmosphere, plants are on the forefront in the battle to combat it.  As stated above, plants reduce C02 levels in a room and not too surprisingly the one major source of CO2 indoors is people.  It is known as bio-effluence but I like to call it breathing, and in some places such as airplanes it can make for some pretty stale air.
3. Air Humidifier - Plants transpire or release moisture to the air through small pores on the undersides of their leaves and in the process humidify the surrounding air.  This evaporative water also can cool the air as much as 4 degrees Fahrenheit, lowering cooling bills.  Again, plants with large leaves will do this the most efficiently.   Spathiphyllums and Philodendrons are two great humidifiers.
4. Volatile Organic Vapor Destroyer – No, we are not talking about the kind of Volatile Organic Vapors that you might get after eating a few too many bean burritos!  These VOC’s are airborne toxic chemical compounds that exude from a variety of sources.   In the interior environment, it is primarily home and office furnishings with plastic or finished wood that contribute the most VOC’s. Off-gassing is the term coined to describe this process (and to think some criticized my use of the word healthifying?)  Some of the worst VOC’s include Formaldehyde, Trichloroethylene Benzene, Toulene, Xylene, and n-Hexane which are known or suspected carcinogens, but others like oxides of Carbon (CO2), Nitrogen (NOx), Sulfur (SOx), and Carbon Monoxide (CO) also persist in the air and create health risks associated with the Asthma, Heart Attack, and Stroke.  Most plants are able to absorb and degrade these air pollutants within a 24 hour period.  How do they do it?  The plants absorb the substances through the pores under their leaves, transport them down to their roots and release them to the microorganisms in the soil that break them down into useful nutrients for the plants.   The reason certain plants, like Golden Pothos (Epiprenum aureum) and Peace Lily (Spathiphylum sp.), are especially good at this is because they have higher transpiration rates than many other indoor plants.  This is all documented in the study done by Margaret Burchett, entitled, “Interior Plants for Sustainable Facility Ecology and Workplace Productivity.”  How many plants it takes to achieve a significant reduction varies depending on the size of the room and the level of pollutants.  According to Ronald Wood of the University of Technology, Sydney, AU, in a study of reduction of VOC’s by potted plants, found that three 6 foot Dracaena plants or six 6″ sized Pothos plants continually reduced the total VOC’s by 50-70% in a room that is 30’x36’x10’.  Even more interesting is that the plants continued to clean the air even during the dark of night when most photosynthesis ceases.  This is demonstrative of the fact that the microorganisms present at the root level are continuing the metabolism of the VOC’s day and night.  Even a relatively low level of VOC’s (100 ppb) can stimulate the plants and microorganisms to begin the process.  According to Dr. Bill Wolverton, the author of the definitive NASA study on indoor air, the 10 best indoor plants for cleaning the air are:
   • Bamboo Palm – Chamaedorea seifritzii
   • Chinese Evergreen – Aglaonema modestum
   • English Ivy – Hedera helix
   • Gerbera Daisy – Gerbera jamesonii
   • Janet Craig – Dracaena deremensis ’Janet Craig’
   • Marginata - Dracaena marginata
   • Mass cane/Corn Plant - Dracaena massangeana
   • Mother-in-Law’s Tongue - Sansevieria laurentii
   • Pot Mum – Chrysanthemum morifolium
   • Peace Lily – Spathiphyllum sp.
   • Warneckii - Dracaena deremensis ‘Warneckii’
5. Noise Suppressor – Plants can act as natural sound buffers, softening loud noises that reflect around a room.  Peter Costa, an engineer who authored, “Constructive use of Vegetation in Office Buildings,” states that plants that are most beneficial are large, full and are densely set with many small leaves rather than having fewer but larger leaves.   They work better in groupings than individually and best suppress noise if placed against walls and corners rather than in the center of a room.  Plants absorb, diffuse and reflect sound waves, so having them placed nearer to a reflecting surface is their most effective use.  They are also much better at quieting high frequencies than low ones (Sometimes I wish I could grow some plants in my ears when the neighbor boy starts to practice his violin!).
6. Stress Reliever / Mood Enhancer – Who couldn’t use a little stress relief these days, but before you think I’m suggesting you smoke your indoor plants, take a look at the study by Margaret Burchett again and you’ll see that she found that just being in the presence of a single plant had an effect of reducing negative mood states by 40-60% for a test group of 55 offices.  Now I’m not saying that plants are as powerful as Prozac, or that they will prevent a disgruntled and unbalanced employee from shooting up the office, but personally I would err on the side of caution and put a few plants around the place.  I mean, what have you got to lose?
7. Room Beautifier – Well, I don’t think you’ll find too many people who wouldn’t agree that plants are a great way to decorate.  They come in a multitude of different colors, shapes, and patterns and there seems to be one for every location whether it is brightly or dimly lit.  There is even anecdotal evidence that patients in the hospital recover faster and require less pain medications when plants are incorporated in their rooms or a view of plants is available to them.  Now that’s healthification!

 Sadly, many people only know indoor plants for their decorative value and are largely unaware of the many benefits they imbue to those who share their spaces.  I hope I’ve brought a few of those benefits to light and brought you all a new sense of appreciation for all the hard work that your indoor plants are doing everyday just for you.  So maybe you’ll stop asking, “What do I get out of it?”

-Patrick