Table 4.
Summary of the study characteristics of the records.
| Source | Participant | Interventions | Comparator | Exposure Duration |
Distance to Plants |
Room Size |
Room Climate |
Study Design |
Functions | Function Category |
Funding | Publication Language |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| [78] | 96 US adults (48 males and 48 females, 80 of whom were college students), age: 18 to 46 | Presence or absence of 17 potted plants in a computer lab | Control | 13.5 × 7.3 × 2.6 m | 27 °C, 38% RH, 420 lux | Field experiment (RCT) |
SBP, reaction time | Physiology, cognition | English | |||
| [53] | 81 US adults | 10 potted plants (accounting 7.16% of the space), 22 potted plants (accounting 17.88% of the space), or no plants in an office | Control | 15–20 min | 12.08 m2, 31.3 m3 | Field experiment (RCT) |
A sorting task, a productivity task | Cognition | English | |||
| [84] | 814 Chinese participants (347 males and 467 females), ethnicity: Asian | A building with or without indoor greening | Survey (non-RCT) |
Neurobehavioral Functioning Evaluation System Testing | Cognition | Sciences and Technology Commission of Shanghai | Chinese | |||||
| [80] | 198 US adults (71 males and 127 females), 176 of whom were college students | 5 potted plants, nonplant objects, no plants in a room | Nonplant objects, control | about 17 min | 3.5 × 6 × 2.4 m | 23 °C, 34% RH, 703 lux | Experiment (RCT) |
Skin temperature, blood pressure, pain tolerance | Physiology, behavior | English | ||
| [83] | 150 US college students (75 males and 75 females), mean age: 19.6 | 9 potted red-flowering geraniums, 9 potted non-flowering geraniums, no plants in a lab | Non-flowering plants, control | 5 min | 1.8 m | 22.4 °C | Experiment (RCT) |
EEG, EDA, finger skin temperature | Physiology | American Horticultural Therapy Association | English | |
| [70] | 146 Japanese college students (83 males and 63 females), ethnicity: Asian | 1 potted 1-m-tall plant placed in front of the participant, the same plant placed on the right-hand side of the participant, no plants in a room | Control | 15 min | 2.345 m in front of and 1.75 m at the side of the participants | 5.81 × 2.78 × 2.35 m | Experiment (RCT) |
An association task, a sorting task | Cognition | English | ||
| [69] | 66 US college students (32 males and 34 females), age: 91% from 18 to 24 | 1 potted flower arrangement (45 × 45 × 45 cm), lavender fragrance, flower and fragrance, or no plants and no fragrance in a lab | Control | 30 min | 3.5 × 2.7 × 2.4 m | 21 °C, 10.6 μmol·m−2·s−1 | Experiment (RCT) |
EEG, EDA, skin temperature | Physiology | English | ||
| [85] | 90 US college female students, mean age: 18.9 | Foliage and flowing plants, flowing plants, or no plants in a lab | Control | 5 min maximum | 1.4 m | 3.9 × 2.3 × 2.7 m | 21.7 °C, 904 lux | Experiment (RCT) |
Pain tolerance, EEG, EDA, finger skin temperature | Behavior, physiology | English | |
| [71] | 90 Japanese college students (35 males and 55 females), ethnicity: Asian | 1 potted 1.5-m-tall plant, a magazine rack put at the same location, or no plants and no magazine racks in a room | A magazine rack, control | 15 min | About 2.9 m in front of the participant | 2.78 × 5.81 × 2.35 m | Experiment (RCT) |
An association task | Cognition | English | ||
| [72] | 38 Taiwanese college students (10 males and 28 females), ethnicity: Asian | Presentation of 6 slides (office without a window view nor indoor plants, office without a window view but with indoor plants, office with a city window view but without indoor plants, office with a city window view and with indoor plants, office with a nature window view but without indoor plants, and office with a nature window view and with indoor plants) in a lab | Control | 15 s for each slide | 3 m | 7 × 5 m | 25 °C | Experiment (non-RCT) |
EEG, EMG, BVP | Physiology | English | |
| [55] | 364 Norwegian office workers, mean age: 43.1 | Presence or absence of potted plants on desks or shelves in an office | Survey (non-RCT) |
Sick leave | Health | English | ||||||
| [68] | 50 healthy Swedish people (23 males and 27 females), mean age: 39.2 | 1 potted flowering begonias (Begonia Elatior) approximately 22 cm high (control plant irrigated with ordinary local tap water; experiment plant irrigated with vortex-rotated local tap water) in an office | Plant irrigated with ordinary local tap water | 10 min for each plant | 5.6 × 3.0 × 2.4 m | 23–24 °C, 36–38% RH, 570–650 lux | Experiment (RCT) |
Heart rate, heart rate variability, power spectral density | Physiology | The Swedish Flower Corporations | English | |
| [63] | 90 South Korean patients who had received appendectomy (52 males and 38 females), mean age: 37.6, ethnicity: Asian | Presence or absence of 12 potted flowering plants in a ward | Control | Field experiment (RCT) |
Pain killer consumption, blood pressure, body temperature, heart rate, respiratory rate | Health, physiology | English | |||||
| [67] | 140 South Korean female high school students, ethnicity: Asian | Presence or absence of plants in 2 classrooms (accounting for 5% of the space) | Control | 14 weeks of school time | Field quasi-experiment (non-RCT, pre-post design) |
Cortisol level, health | Physiology, health | English | ||||
| [86] | 89 US sophomores | Presence or absence of plants in a classroom | Control | 1 semester of class time | Field quasi-experiment (non-RCT) |
Course grade | Cognition | English | ||||
| [65] | 76 Taiwanese junior high school students (58 males and 18 females), mean age: 13.55, ethnicity: Asian | Presence or absence of 6 potted plants (about 135 × 80 cm, having a green coverage ratio of 6%) in a classroom | Control | 12 weeks of school time | Field quasi-experiment (non-RCT) |
Sick leave, misconduct | Health, behavior | English | ||||
| [64] | 80 South Korean female patients who had received thyroidectomy, mean age: 36.2, ethnicity: Asian | Presence or absence of 12 potted flowering plants in a ward | Control | Field experiment (RCT) |
Pain killer consumption, hospitalization days | Health | English | |||||
| [87] | 34 Norwegian college students (12 males and 22 females), mean age: 24.15 | Presence or absence of 4 potted plants (2 flowering pink Phalaenopsis, 1 30-cm-tall Aglaonema commutatum, and 1 120-cm-tall Schefflera arboricola) in an office | Control | 60 min | 3.9 × 2.1 × 3.6 m | Experiment (RCT) |
The Reading Span Task | Cognition | English | |||
| [66] | 36 Taiwanese junior high school students (18 males and 18 females), mean age: 12.41, ethnicity: Asian | Taking care of 34 potted plants inside and outside a classroom (with a green coverage ratio of 6.3% indoors) | Control | 18 weeks of school time | Field experiment (RCT) |
Examination score | Cognition | Chinese | ||||
| [73] | 30 Chinese college students (15 males and 15 females), ethnicity: Asian | Presentation of 5 photos of vegetation landscapes and a blank in a room | Control | 2 min | 0.5 m | 7 × 4 × 3 m | 25 °C, 40% RH | Experiment (RCT) |
ECG, blood pressure, heart rate, GSR, fingertip pulse | Physiology | English | |
| [74] | 30 Chinese college students (15 males and 15 females), age: 18 to 24, ethnicity: Asian | Presentation of 12 photos of flowers and a blank in a room | Control | 2 min | 0.5 m | 7 × 4 × 3 m | 25 °C, 40% RH | Experiment (RCT) |
Blood pressure, heart rate, GSR, fingertip plus | Physiology | National Key Technology Research and Development Program in China |
English |
| [88] | 29 Japanese college students (14 males and 15 females), age: 19 to 24, ethnicity: Asian | Potted Hedera helix L. (60 × 40 cm) of 5 different colors on a table in a room | Different colors of the plant | 1 min for each plant color | 0.5 m | Experiment (RCT) |
Brain activity, eye movement | Cognition | Egyptian Ministry of Higher Education | English | ||
| [89] | 28 Japanese undergraduate and graduate students (14 males and 14 females), mean age: 21.42, ethnicity: Asian | Placement of 1 potted plant of 3 different colors on a table in a room | Different colors of plants | 1 min for each plant color | 1.5 m | 59.4 m2 | 23 °C, 55% RH, 700 lux | Experiment (RCT) |
Eye movement, brain activity | Cognition | Egyptian Ministry of Higher Education | English |
| [79] | 30 South Korean college students (15 males and 15 females), mean age: 23.5, ethnicity: Asian | Placement of potted plants (60 × 40 cm) of 5 different colors on a box in a classroom | Different colors of plants | 3 min for each plant color | 1 m | 7 × 4.5 × 2.8 m | 25 °C, 70% RH, 700 lux | Experiment (RCT) |
EEG | Physiology | English | |
| [58] | Study 3: 33 British adult office workers (16 males and 17 females), mean age: 28 | Study 3: presence or absence of 8 potted plants (average height 90 cm) in an office | Control | Study 3: Field experiment (RCT) |
An information management and processing task, a vigilance task | Cognition | English | |||||
| [81] | 16 Chinese college students (8 males and 8 females), mean age: 23.5, ethnicity: Asian | Presence of potted plants of the combinations of 3 colors, 3 scents, and 3 sizes on a table in an office | Combinations of plant colors, scents, and sizes | 10–15 min | 22 °C, 41.65% RH, 0.2 ms−1 wind velocity | Experiment (RCT) |
EEG, ECG, oxyhaemoglobin saturation, fingertip blood flow, skin resistance, respiration rate | Physiology | Sciences and Technology Commission of Shanghai | English | ||
| [82] | 24 South Korean male adults, mean age: 24.9, ethnicity: Asian | A plant transplanting task, a computer operation task on a table in a greenhouse room | A computer task | 15 min | 20.8 °C, 57.7% RH, 1365.5 lux | Experiment (RCT) |
Heart rate variability, blood pressure, pulse rate | Physiology | English | |||
| [54] | 565 Norwegian office workers | Outdoor nature contact, indoor nature contact, and outdoor view through windows | Survey (non-RCT) |
Sick leave | Health | English | ||||||
| [61] | 270 Pakistani surgical patients, ethnicity: Asian | Presence or absence of foliage plants and flower arrangements in a ward | Control | Field experiment (RCT) |
Blood pressure, heart rate, respirationrate, body temperature, hospitalization days, analgesics consumption | Physiology, health | The University of Agriculture Peshawar in Pakistan | English | ||||
| [90] | 30 Egyptian male college students, age: 22 to 37, ethnicity: African | Potted Hedera helix L. (60 × 40 cm) of 5 different colors on a table in a room | Different colors of the plant | 1 min for each plant color | 0.5 m | 59.4 m2 | 21 °C, 55% RH | Experiment (RCT) |
Eye movements, brain activity | Cognition, physiology | Egyptian Ministry of Higher Education | English |
| [91] | 5 Indonesians, ethnicity: Asian | A room with 5 potted plants and a room without plants | Control | 30 min | Experiment (non-RCT) |
Heart rate, blood pressure | Physiology | Ministry of National Education in Indonesia | English | |||
| [77] | 66 Hong Kongese college students (40 males and 26 females), mean age: 25.6, ethnicity: Asian | A basement room with plants, with a fake window, with plants and a fake window, and without plants nor a window | Control | At least 8 min | 3.3 × 2.2 × 2 m | 24 °C | Experiment (non-RCT) |
EDA, a response time task | Physiology, cognition | Hong Kong Polytechnic University | English | |
| [75] | 28 US adults (12 males and 16 females), age: 23 to 42 | Presence or absence of plants in an actual environment and a virtual one | Control | 5 min | Experiment (RCT) |
Heart rate, EDA, blood pressure, a visual reaction time task, The Stroop task, a visual backward digit span task | Physiology, cognition | Campus Sustainability Innovation Fund, Harvard University Office for Sustainability |
English | |||
| [57] | 36–41 Japanese office workers, mean age: 33.95, ethnicity: Asian | Presence (3–10% green coverage ratio) or absence of plants in 2 offices | Control | 16 weeks of working hours | 132 m2 (321 m3), 270 m2 (675 m3) | Field quasi-experiment (non-RCT) |
Heart rate, salivary amylase activity, critical flicker fusion frequency, fingertip pulse wave | Physiology | Grant-in-Aid for Scientific Research, Japan Society for the Promotion of Science | English | ||
| [60] | 50 Chinese female elders with hypertension, mean age: 79.2, ethnicity: Asian | Presence or absence of 1 potted plant on a table in a room | Control | 5 min | 0.38 m | 23 °C, 40% RH, 500 lux, | Experiment (RCT) |
Blood pressure, EEG | Physiology | English | ||
| [76] | 100 Taiwanese elders, age: >65, ethnicity: Asian | Presence or absence of plants in houses | 1 year | Survey (non-RCT) |
Blood pressure, heart rate | Physiology | Ministry of Science and Technology in Taiwan | English | ||||
| [59] | 63 adult Japanese office workers (33 males and 30 females), mean age: 40.15, ethnicity: Asian | Presence or absence of 1 potted plant (15–20 cm tall, 7–10 cm wide) on the desk in an office | Control | 3 min | 1260 m2 | 20–24 °C, 40–50% RH, 500–700 lux | Field experiment (non-RCT, pre-post design) |
Pulse rate | Physiology | English | ||
| [56] | 30 Chinese female office workers, mean age: 29.42, ethnicity: Asian | Presence or absence of 1 potted plant with blue or purple flowers on a desk in an office | Control | 3 min | 0.4 m | 21 °C, 50% RH, 300 lux | Field quasi-experiment (non-RCT, pre-post design) |
EEG, heart rate variability, skin conductance | Physiology | National Nature Science Foundation of China | English | |
| [92] | 33 Chinese elders, age: 65 to 99, ethnicity: Asian | Combination of potted succulents (3–10 cm tall, 3 cm wide) or flower arrangement (50–60 cm tall, 5–18 cm wide) performed indoors | Flower arrangement | 25 min | Experiment (RCT) |
Salivary cortisol | Physiology | National Nature Science Foundation of China | Chinese | |||
| [62] | 34 Chinese elders with dementia (13 males and 21 females), ethnicity: Asian | With or without a treatment course of indoor horticultural activities (sowing, transplanting seedlings, succulents potting, and herbal flower potting) | Control | 30 min | Experiment (non-RCT) |
Blood pressure, heart rate, ECG | Physiology | National Nature Science Foundation of China, Beijing Science and Technology Project Foundation | Chinese | |||
| [93] | 44 Chinese elders living alone, ethnicity: Asian | Four kinds of indoor horticultural activities (sowing, transplanting seedlings, succulents potting, and herbal flower potting) | Within- participants, between-participants | 30 min | Experiment (non-RCT) |
Blood pressure, heart rate, ECG | Physiology | Beijing Science and Technology Commission Green Communication Foundation | Chinese | |||
| [94] | Study 1: 120 South Africans, mean age: 33.72, ethnicity: African | Presence of 3 potted plants, 6 plant pictures on 3 walls (80 × 80 cm), and no potted plants and plant pictures in an office | Control | 35 min | 3 × 3 m | 21 °C, 510 lux | Experiment (RCT) |
A card-sorting task, a reading task | Cognition | English |
RH: relative humidity; SBP: systolic blood pressure; DBP: diastolic blood pressure; EEG: electroencephalography; EDA: electrodermal activity; EMG: electromyography; BVP: blood volume pulse; ECG: electrocardiography; GSR: galvanic skin response; RCT: randomized controlled trial; non-RCT: not randomized controlled trial.