Indoor Plants and Gardens

References about Health Benefits of Indoor Plants

Examples of healthcare facilities with indoor gardens and atria will be added to this page soon, so please check back.

Additional reference suggestions are always welcome.

Many thanks to TLN summer intern Meaghan Collins for help compiling this list.

Bringslimark, Tina and Terry Hartig, and Grete Patil (2009). “The Psychological Benefits of Indoor Plants: A Critical Review of the Experimental Literature.” Journal of Environmental Psychology, Vol. 29, No. 4, pp. 422-433.
Abstract: “People have been bringing plants into residential and other indoor settings for centuries, but little is known about their psychological effects. In the present article, we critically review the experimental literature on the psychological benefits of indoor plants. We focus on benefits gained through passive interactions with indoor plants rather than on the effects of guided interactions with plants in horticultural therapy or the indirect effect of indoor plants as air purifiers or humidifiers. The reviewed experiments addressed a variety of outcomes, including emotional states, pain perception, creativity, task-performance, and indices of autonomic arousal. Some findings recur, such as enhanced pain management with plants present, but in general the results appear to be quite mixed. Sources of this heterogeneity include diversity in experimental manipulations, settings, samples, exposure durations, and measures. After addressing some overarching theoretical issues, we close with recommendations for further research with regard to experimental design, measurement, analysis, and reporting.” (From website cited below.)
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Chang, Chen-Yen, and Ping-Kun Chen (2005). “Human response to window views and indoor plants in the workplace.HortScience, Vol. 40, No. 5, pp. 1354–9.
Abstract: “The purpose of this paper was to report the effects of window views and indoor plants on human psychophysiological response in workplace environments. The effects of window views and indoor plants were recorded by measuring participant’s electromy-ography (EMG), electroencephalography (EEG), blood volume pulse (BVP), and state-anxiety. Photo Impact 5.0 was used to simulate the environment in an office, where six conditions were examined: 1) window with a view of a city, 2) window with a view of a city and indoor plants, 3) window with a view of nature, 4) window with a view of nature and indoor plants, 5) office without a window view, and 6) office without a window view and indoor plants. Participants were less nervous or anxious when watching a view of nature and/or when indoor plants were present. When neither the window view nor the indoor plants were shown, participants suffered the highest degree of tension and anxiety.”
Keywords: Indoor Plants, Workplace
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More on Chang, Chen-Yen, and Ping-Kun Chen, from Research Design Connections, “Workplace Windows and Plants – Identifying the Best Stress Relievers.”
It seems intuitive that outdoor views and plants can decrease stress for office workers. But how might plants and views affect people when used together? Chen-Yen Chang and Ping-Kun Chen of the National Chung Hsing University in Taiwan provide some new information using physiological measures and questions on mood state.

Nature View Favored Over City View
Chang and Chen created one side of an office interior, and then modified it. They produced slides of six different scenes: a windowless office, an office with a city view, and an office with a natural environment view. Three more scenes were created by adding plants to each of the previous situations. They then tested students’ reactions to these slides, measuring brain waves, forehead muscle tension, and cardiovascular response to stress. Those tested also responded to surveys about how they felt when viewing each slide.

The cardiovascular response to stress was the most sensitive, showing significant differences in responses between the windowless office and each of the other five conditions.

With the exception of the city view without plants, which raised the average stress level (measured by a greater blood volume pulse), the comparisons showed a reduction in stress. The lowest average reading was during presentation of the slide with a natural view and no plants. (See chart 1 for details.) The higher reading for a natural view with plants may be due to the increase in distraction from both being present.

Self-Report Indicates Different Results
When students reported how anxious they felt, however, the windowless office rated the lowest, with the students reporting the city view being less anxious (higher questionnaire score) than the windowless office, and the natural view slide and the natural view slide with plants both as less anxious than the city view.

Study Implications
This study confirms previous research that views of nature can reduce stress. It also confirms that plants in windowless offices and in offices with a city view can decrease stress over those environments where plants are not present. This study raises interesting questions about the effect of city views in reducing stress, which call for further research.

Dijkstra, K., M.E. Pieterse, and A. Pruyn (2008). “Stress-reducing effects of indoor plants in the built healthcare environment: The mediating role of perceived attractiveness.” Preventive Medicine, Vol. 47, No. 3, pp. 279-283. To purchase full report:
Abstract: “Natural elements in the built healthcare environment have shown to hold potential stress-reducing properties. In order to shed light on the underlying mechanism of stress-reducing effects of nature, the present study investigates whether the stress-reducing effects of indoor plants occur because such an environment is perceived as being more attractive.”

Keywords: Indoor Plants, Meditation, Healthcare

Dravigne, Andrea and Tina Waliczek, R. Lineberger, and J. Zajicek. 2008. “The Effect of Live Plants and Window Views of Green Spaces on Employee Perceptions of Job Satisfaction.HortScience, Vol. 43, p. 279. To access full report:
Keywords: Indoor Plants, Workplace

Han, Ke-Tsung (2008). “Influence of Limitedly Visible Leafy Indoor Plants on the Psychology, Behavior, and Health of Students at a Junior High School in Taiwan.Environment and Behavior, Vol. 41, No. 5, pp. 658-692.
Abstract: “There is growing evidence to support the notion that contact with nature is helpful for emotional states, attention, mental fatigue, behavior, and personal health. This study adopts a quasi-experimental approach to investigate the effects of limitedly visible indoor plants on students’ psychology, physiology, and behavior and uses a control-series design covering one semester.” (From website cited below.)
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Keywords: Children’s Education, Indoor Plants

Heerwagen, Judith. References to be added soon.

Larsen, Larissa and Jeffrey Adams, Brian Deal, Byoung-Suk Kweon and Elizabeth Tyler (1998). “Plants in the workplace: The effects of plant density on productivity, attitudes, and perceptions.Environment and Behavior, Vol. 30, No. 3, pp. 261-81.
Abstract: “This experiment measures the effects of indoor plants on participants’ productivity, attitude toward the workplace, and overall mood in the office environment. In an office randomly altered to include no plants, a moderate number of plants, and a high number of plants, paid participants (N = 81) performed timed productivity tasks and completed a survey questionnaire. Surprisingly, the results of the productivity task showed an inverse linear relationship to the number of plants in the office, but self-reported perceptions of performance increased relative to the number of plants in the office. Consistent with expectations, participants reported higher levels of mood, perceived office attractiveness, and (in some cases) perceived comfort when plants were present than when they were not present. Decreased productivity scores are linked to the influence of positive and negative affect on decision making and cognitive processing.” (From website cited below.)
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Keywords: Indoor Plants

Lohr, V.I., Pearson-Mims, C.H. and Goodwin, G.K. 1996. “Interior plants may improve worker productivity and reduce stress in a windowless environment.Journal of Environmental Horticulture, Vol. 14, pp. 97-100.

Mapes, Diane (2009). “Looking at Nature Makes You Nicer.” MSNBC, Oct. 14.
“Nature’s psychological power is so profound, in fact, that even paying attention to a painting of roses or a potted fern can make a difference in a person’s attitude. In three of the experiments, people were shown images on a 19-inch computer screen, with half viewing buildings, roads and cityscapes and the other half viewing landscapes, lakes and deserts.”

Nakamura, R. and E. Fujii (1990). “Studies of the characteristics of the electroencephalogram when observing potted plants: Pelargonium hortorum “Sprinter Red” and Begonia evansiana.” Technical Bulletin of the Faculty of Horticulture of Chiba University, 43: 177-183. (In Japanese with English summary).
Summary: Nakamura and Fujii have carried out two studies in Japan (1990, 1992) that measured brain wave activity as unstressed persons (non-patients) looked either at plants or human-made objects. In an intriguing first experiment, the researchers analyzed alpha rhythm activity as subjects viewed: two types of potted plants, each with and without
flowers (Pelargonium and Begonia); the same pots without plants; or a cylinder similar to the pots (Nakamura and Fujii, 1990). Results suggested that persons were most wakefully relaxed when they observed plants with flowers, and least relaxed when they looked at pots without plants. In the second study they recorded the electroencephalogram (EEG) while persons were seated in a real outdoor setting and viewed a hedge of greenery, a
concrete fence with dimensions similar to the hedge, or a mixed condition consisting of part greenery and part concrete (Nakamura and Fujii, 1992). The EEG data supported the conclusion that the greenery elicited relaxation whereas the concrete had stressful influences.

Park, Seong-Hyun and Richard Mattson (2008). “Effects of Flowering and Foliage Plants I Hospital Rooms on Patients Recovering from Abdominal Surgery.” HortTechnology, Vol. 18, pp. 549-745.
Link here to ashs press release.

Raanaas RK, Evensen KH, Rich D, Sjöström G, Patil G (2011). “Benefits of indoor plants on attention capacity in an office setting.” Journal of Environmental Psychology, Vol. 31, No. 1, Mar. pp. 99-105.
“This research studied possible benefits of indoor plants on attention capacity in a controlled laboratory experiment. Participants were 34 students randomly assigned to one of two conditions: an office setting with four indoor plants, both flowering and foliage, or the same setting without plants. Attention capacity was assessed three times, i.e. immediately after entering the laboratory, after performing a demanding cognitive task, and after a five-minute break.” (from abstract cited below)
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Shibata, Seiji and Naoto Suzuki (2002). “Effects of the Foliage Plant on Task Performance and Mood.”Journal of Environmental Psychology, Vol. 22, No. 3, pp. 265-272.
Synopsis by InformeDesign: “This study investigated how the presence of a leafy plant in the room affected mood and task performance. Previous research studied the effects of nature in hospitals, prisons, and residential settings and suggested that natural views from windows may be distracting when performing tasks that require concentration (e.g., filing, computing), however the effects of nature in the workplace have not been fully studied…Plants may relieve fatigue or stress, increase feelings of well-being, or enhance indoor environments, such as workplaces.”
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Tse, M. M. Y. (2010).“Therapeutic effects of an indoor gardening programme for older people living in nursing homes.” Journal of Clinical Nursing, Vol. 19, No. 7-8, April, pp. 949-58.
Synopsis: “To explore the activities of daily living and psychological well-being of older people living in nursing homes and also to examine the effectiveness of a gardening programme in enhancing socilaisation and life satisfaction, reducing loneliness and promoting activities of daily living for older people living in nursing homes.”
To explore the activities of daily living and psychological well-being of older people living in nursing homes and also to examine the effectiveness of a gardening programme in enhancing socilaisation and life satisfaction, reducing loneliness and promoting activities of daily living for older people living in nursing homes.
Life in nursing homes can mean very limited physical and social activity, leading to further decline in function for many older people.
This was a quasi-experimental pre and posttest control group design.
Older people from nursing homes were invited to join the eight week indoor gardening programme (experimental group), while older people in other nursing homes were treated as the control group; they received regular care without the eight week indoor gardening programme. There were 26 older people (25 female and one male; mean age 85 years) in the experimental group and 27 (20 female and seven male; mean age 82 years) in the control group. Demographic data including age, gender, educational level and financial situation were collected, in addition to information regarding life satisfaction, loneliness, physical activity and social network situation, before and after the eight week indoor gardening programme for both the experimental and control groups. Also, details of experimental group subjects’ experience of the indoor gardening programme were elicited using open-ended questions.
There were significant improvements in life satisfaction and social network and a significant decrease in perception of loneliness for older people in the experimental group after the eight week indoor gardening programme, while the activities of daily living were unchanged for both groups after the programme.
Relevance to Clinical Practice
Given the positive effects of gardening activities, it is suggested that they be promoted more widely among nursing home residents.
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Ulrich, Roger S. References to be added soon.