Plants in the indoors

Let us do a small experiment. Take a look at these two pictures. Imagine these two desks and you being present in that work space. Do these spaces exude different emotions to you? Which desk would you rather like spending your day working on?

Picture: Desks, without and with plants

It isn’t that difficult a decision, isn’t it? It is desk number 2. Plants do make an impact. Why? Well the very first answer would be that plants adds beauty, colour and life to our space. And it is true! But these are simply our visual perception of the presence of plants in the space. Let’s take a step further and try to understand this beyond the basics.

Plants have unbridled benefits to our body and mind. Many researches have supported this thesis.

Effects on our body

• Air-purifiers

We all know plants absorb CO₂ gases present in the air for photosynthesis only to replace it with oxygen and improves air quality. NASA report ‘Interior landscape plants for indoor air pollution abatement, 1989’ suggest that it also removes other harmful air pollutants like, benzene, formaldehyde and trichloroethylene often present indoors. This becomes immensely crucial at the time when we spend around 70-90% of our days indoors. The report has also suggested a number of common plants that are excellent air-purifiers. Some examples are palm tree, money plant, chinese evergreen, ficus, ferns, snake plant, zz plant and peace lily.

The influence of interior plants on dust accumulation has also been explored (Lohr and Pearson-Mims, 1996). Adding plants to the periphery of a room reduced particulate matter deposition by as much as 20%, even in center of the room many meters from the plants.

• General health improvement

Poor quality indoor air can lead to health problems like headaches, eye fatigue, throat irritation and asthma. In a study in Norway, workers in an office with foliage plants reported fewer physical symptoms, including coughing, hoarse throat, higher blood pressure and fatigue, than when no plants were present (Fjeld, 2000). Results of a study of elderly residents in an assisted living facility who participated in a project to grow indoor plants in their rooms found that they reported significantly improved feelings of health after working with the plants (Collins and O’Callaghan, 2008).

• Comfort (Lohr, 2010)

The recommended relative humidity for human comfort is 30%- 60% and many of our indoors are well below that range. Foliage plants can raise relative humidity to healthier and more comfortable levels in interior spaces (Lohr, 1992). Indoor plants also help regulating temperatures. A study conducted by Costa and Lothian examined the effects of interior plants on acoustics in interior spaces (Freeman, 2003). They showed that plants can reflect, diffract, or absorb sounds, depending on the frequency and plants worked best at reducing high frequencies sounds in rooms with hard surfaces.

• Pain tolerance (Lohr, 2010)

Pain tolerance is also increased in the presence of interior plants among people who are not in acute pain (Lohr and Pearson-Mims, 2000; Lohr and Pearson-Mims, 2008). Subjects were tested in a room with one of three treatments: control, added colorful nonplant objects, or added plants. Perceptions of physical discomfort were lower in the room with plants than in the room without plants or the room with colorful objects. This demonstrated that the positive benefits of plants are not simply associated with their decorative value or their use as a distraction to help keep one's mind off of the discomfort.

“The biophilia hypothesis is that we have an innate need to be connected to nature. We evolved in nature so our brains are more relaxed when we are connected to nature and that is all connected to wellbeing. It’s like the difference between how you are after a good night’s sleep compared to having an okay but not great night.” -Dr Dominque Hes, Thrive Research Hub, Melbourne School of Design, University of Melbourne.

Effects on our mind

• Psychological impacts

Health benefits of adding plants to the workspace are multifold. Plants help increase positivity and make us feel more energised. They can help with loneliness and ease depression. Seeing the plant grow every day and caring for it acts as a great mood uplifter. Various studies have shown immense impact on reducing stress and improving mental well-being. Being around plants makes us more relaxed. Plants such as orchids, succulents, snake plant and aloe vera which can release oxygen at night too enabling a good night sleep.

• Productivity

Productivity has been shown to be higher when plants are present. Plants have positive effects on visual concentration, mental processing, and manual dexterity. Working in spaces with plants enhances our creativity and efficiency. Mental fatigue has also been shown to be reduced by plants (Tennessen and Cimprich, 1995).

References:

Collins, C.C. and O’Callaghan, A.M. 2008. The impact of horticultural responsibility on health indicators and quality of life in assisted living. HortTechnol. 18:611-618.
Fjeld, T. 2000. The effect of interior planting on health and discomfort among workers and school children. HortTechnol. 10:46-52.
Freeman, K. 2003. Plants and their acoustic benefits. http://www.plants-inbuildings.com/acoustic.php.
Lohr, V.I. 1992. The contribution of interior plants to relative humidity in an office. p. 117-119. In: D. Relf (ed.), The Role of Horticulture in Human Well-being and Social Development. Timber Press, Portland, Oregon.
Lohr, V.I. 2010. What are the benefits of plants indoors and why do we respond positively to them? Acta Horticulturae 881(2):675-682.
Lohr, V.I. and Pearson-Mims, C.H. 1996. Particulate matter accumulation on horizontal surfaces in interiors: Influence of foliage plants. Atmospheric Environ. 30:2565- 2568.
Lohr, V.I. and Pearson-Mims, C.H. 2008. People's response to discomfort in the presence of interior plants or art. Acta Hort. 790:173-178.
Tennessen, C.M. and Cimprich, B. 1995. Views to nature: Effects on attention. J. Environ. Psychol. 15:77-85.

Wolverton BC, Douglas WL, Bounds K. 1989. A study of interior landscape plants for indoor air pollution abatement U.S. National Aeronautics and Space Administration.