Course:SOWK551/2021/Use of Horticultural Therapy on Mental Health in Healthcare

From UBC Wiki
Two people working in a garden

Short Summary

Literature review on using horticultural therapy on patients suffering from mental illness in healthcare setting and social work practice.

Author: Davis T.

Date: December 9, 2022


Mental health is one of the outstanding healthcare issues in the world (World Health Organization (WHO), 2022).  Per Bland et al. (2021), mental health is a specialist social work practice, and general social workers in various fields of practice have been employed in working with individuals’ mental health concerns as a part of psychosocial interventions.  Mental health service providers adopted various evidence-based clinical practice models in their work.  Horticulture Therapy has been long used as a therapeutic activity for people suffering from mental illnesses (Siu et al., 2020).  This literature review aims at providing an overview of the effectiveness of the application of Horticultural Therapy on Mental illness Patients in healthcare and its relevance to social work practice.

Definition of Horticultural Therapy

Horticultural therapy (HT) is a clinical practice model that uses plants, horticultural activities, and the garden landscape to promote holistic well-being for service users to achieve clinically outlined goals (Canadian Horticultural Therapy Association (CHTA), 2022; Cipriani et al., 2017; Kam & Siu, 2010).  The goals are measurable, and the outcome of HT is expected to bring a sense of accomplishment.  In practicing HT, participants are generally invited to take care of plants during therapy and counselling sessions; they are guided to experience the growth process of the plants in healing gardens; and therapists should make use of the multi-sensory characteristics of plants during the program (Siu et al., 2020).

HT is often considered interchangeable with ‘therapeutic horticulture’ (Cipriani et al., 2017), which is the process to improve participants’ health and wellness through plants and related activities (CHTA, 2022).  Compared to HT, goals and defined outcomes of therapeutic horticulture are not necessarily considered nor clinically documented (CHTA, 2022).  The general public can practice therapeutic horticulture on their own without the presence of HT practitioners. .

Effectiveness on Mental Health

In accordance with WHO (2022), an estimated 970 million people were living with a mental illness worldwide, which accounted of 13% of the global population in 2019.  There was an anticipated 27% rise in the global prevalence of mental disorders after the COVID-19 pandemic (Santomauro et al., 2021; WHO, 2022).  

Canadian Institute for Health Information (2019) and Smetanin et al. (2011) revealed that 20% of Canadians experienced a mental illness in their lives; about 38% of Canadians reported that their symptoms started before the age of 15, and half of Canadians have experienced or developed a mental illness when they reached 40 years old.  About 17% of British Columbians, approximately 800, 000 people, were experiencing a mental illness or substance use issue (Canadian Mental Health Association Mental, 2022).

HT has been long used extensively as a non-pharmacological intervention for people with mental illnesses, such as schizophrenia and depression, and promoting mental health in rehabilitative, vocational, and community settings (Clatworthy et al., 2013; Tu, 2022).  Participants would engage in goal-orientated HT in the form of active gardening and the passive appreciation of nature alongside counseling.  HT is proven to be effective in working with patients with mental illness in terms of generating emotional benefits to patients, such as reducing psychiatric symptoms and stress, and increasing the sense of tranquility, mood stabilization and enjoyment (Han et al., 2018); reducing fatigue and restore attention and cognitive ability (Berman et al., 2008); increasing self-efficacy, self-esteem, and quality of life (Siu et al., 2020); as well as improving decision-making and delivering a sense of perceived control and empowerment (Kenmochi et al., 2019; Tu, 2022).  Moreover, group HT provides an opportunity for patients to have group cohesiveness and a sense of belonging (Siu et al., 2020).

HT benefits mental health due to its ability to restore attention, and promote social cohesion and connectedness (Chen et al., 2013; Ng et al., 2021; Tu, 2022).  According to the attention restoration theory, HT program activities involve being in touch with plants and nature to focus on here-and-now, distract participants from negative emotions and reduce feelings of depression and anxiety (Kenmochi et al., 2019).  The horticultural activity in a natural environment generates a feeling of distancing from hustle daily lives or the urban environment, which is critical in promoting mental health and reducing mental fatigue (Tu, 2022). Patients can engage in purposeful activities and develop a sense of accomplishment and productivity, as well as develop sustainable vocational skills and productivity in horticulture (Siu et al., 2020).

Healing Garden

Healing garden or therapeutic garden, interchangeably, is imperative in delivering HT.  It a nature-oriented space aimed at providing therapeutic or rehabilitative potential benefits and maximum influence on health to participants (Söderback et al., 2004).  It acts as a place of sanctuary to meet one’s desire for contact with nature, in particular in the metropolis and developed urban cities (Söderback et al., 2004).  Healing gardens should a prevalence of green material throughout seasons, encourage exercise, minimize intrusions and ambiguity (Marcus & Barnes, 1999).  In addition to a plentiful variety of plant materials that attract birds and butterflies, healing gardens also consist of leaves that move with breeze, and pools have fish. Healing gardens should be open to all and give a sense of familiarity. It should be tranquil and peaceful so that its voices, such as birdsong and water-splash, can be heard, and facilitate non-discrimination with high accessibility.  (Söderback et al., 2004).

Horticultural Therapy in Healthcare

HT is considered an alternative treatment option in rehabilitation for patients suffering from chronic mental disorders. Evidence has shown that HT significant benefits multiple populations of hospitalized patients including paediatric, geriatric, and psychiatric patients (Knotos et al., 2021).  The diverse structure of HT benefits patients in terms of mental well-being, stress and coping, self-esteem, cognitive function, and interpersonal relationships (Siu, Kam & Mok, 2020).

In Canada, gardens are commonly found in hospitals for therapeutic practice.  There are gardens in hospitals throughout Metro Vancouver designed for patients, friends, relatives, and staff such as Banfield Pavilion in Vancouver General Hospital, the garden in Royal Columbia Hospital, and the rooftop garden in St Paul’s Hospital … etc.  Healing gardens can improve the quality of a hospital’s physical environment which provides positive patient medical outcomes and care quality.  For instance, long-stay and paediatric hospitals are suggested to have gardens access to grounds, parks, and playgrounds the US (Söderback et al., 2004).  

HT can also be used for influencing health and well-being by viewing photographs, slides, and videos of outdoor nature and garden scenes (Söderback et al., 2004).   These are beneficial to patients with low mobility or bedridden patients.  In terms of promoting patients’ health, well-being, and quality of life, in addition to the positive outcomes on one’s emotional skills, HT is often used by occupational therapy professionals in hospitals to address the performance needs of clients in areas of occupation such as activities of daily living (Cipriani et al., 2017).

Critiques & Application to Social Work Practice

Mental health assessment is a common topic in HT studies.  Existing studies have explored the outcome of HT on mental health with reported positive results (Kenmochi et al., 2019; Zhu et al., 2016). Nevertheless, there are critiques of the results, that the studies are inconsistent due to the different tools used in assessing mental health (Kam & Siu, 2010; Nicholas et al., 2019).  The results have also been disturbed by factors including report quality, suitable control group randomization, study participants, and blinding methods.  The randomized controlled trials of HT research were indicated to lack strength of evidence and gave rise to non-significant results in some existing studies (Nicholas et al., 2019).

There is inadequate evidence of the prospective advantages of HT for hospitalized patients.  Despite the increasing prevalence of HT and therapeutic horticulture implementation in healthcare, most literature has merely focused on the advantages of therapeutic horticulture and social horticulture through exploratory analyses (Cipriani et al., 2017).  The validity was reduced by the small sample size and incomplete narrative of actual HT interventions (Clatworthy et al., 2017).

Though HT is a recognized profession, service providers does not have to be trained horticultural therapists to implement HT. Practitioners from diverse settings including hospitals, hospices, rehabilitation facilities, botanical gardens, and private practice could provide HT to participants (Cipriani et al., 2017).  Alongside recreational therapists, physical therapists and occupational therapists, social workers are also an example of common practitioners who can utilize HT within their scope of practice (Horticultural Therapy Institute, 2022).  However, most of the existing literature about HT is written by recreational therapy professionals, occupational therapy professionals, or nursing professionals.  There lacks literature on the social work perspectives.  

Since mental health is one of the major service scopes of social work practice (Bland et al., 2021), it is imperative for social work practitioners to understand the available resources and work in the multi-disciplinary team, or equip with effective clinical practice models for rendering therapeutic intervention and assessment.  HT is suitable for social work as it aligns with the social work values of a client-centered approach and person-in-environment perspectives.  Healing gardens also associate with social workers’ mission of social justice and anti-oppressive practice in terms of addressing cultural sensitivity and high accessibility.  Moreover, HT also acts as an intervention addressing patients’ needs in the social determinant of health perspective.

In addition to implementing HT in clinical practice or using it as a resource for system navigation, social workers can conduct high-quality social research on HT for exploring the related issues and concerns with social work perspective and promoting social justice, for instance, social workers can utilize the intersectionality lens and anti-oppressive practice in conducting critical research with providing strong evidence.


HT was shown to be a safe and feasible non-pharmacological intervention in healthcare.  Lin et al (2021) recommend that HT should be promoted in nursing homes, communities, hospitals, and even families.  Healthcare professionals are recommended to apply HT to different populations, especially there are increased loneliness in the population, such as older adults due to the post-pandemic influence.  Developing HT intervention could bring a positive influence on the physical and psychological well-being of the society.  Furthermore, HT is important in public mental health. Literature suggested that HT should be considered valuable for cultivating mental health by healthcare service providers and to be integrated into medical, healthcare, and community settings to promote mental health (Tu, 2022).

There are regulatory bodies for horticultural therapist professionals in North America, Conversely, HT was not widely used as mainstream medicine practitioners considered that there needs to be more substantial in favor of the beneficial effects of HT based on evidence-based medicine (Tu 2022).  For future research, there could be more robust and larger sample sizes for higher levels of evidence and minimizing error.  More studies should focus on HT interventions and healing gardens with clinically designed goals instead of simply focusing on horticulture-based interventions such as therapeutic horticulture and social horticulture (Cipriani et al., 2017).  Future studies could also observe the changes in participants’ interest in plants, and their horticultural knowledge and skills so as to have holistic evidence for determining the long-lasting effect of HT (Siu et al., 2020).  

Eventually, Cipriani et al. (2017) suggested that more studies should be carried out by various healthcare professionals, for instance, social workers and physical therapists.  Therefore, outcomes of interest to the related profession can be comprised in subsequent studies.


In conclusion, this paper reviewed recent literature and has found significant effectiveness of horticulture therapy on mental health.  Social workers are recommended to apply HT in their clinical practice and to conduct high-quality research in this model.


Berman, M. G., Jonides, J., & Kaplan, S. (2008). The cognitive benefits of interacting with nature. Psychological Science, 19(12), 1207–1212.

Bland, R., Drake, G., & Drayton, J. (2021). A starting point Understanding social work in mental health. In Social Work Practice in Mental Health: An introduction (3rd ed.). essay, Routledge.

Canadian Horticultural Therapy Association . (2022). What is Horticultural Therapy? . Canadian Horticultural Therapy Association . Retrieved December 9, 2022, from

Canadian Mental Health Association Mental. (2022). Canadian Mental Health Association Mental Health for all. Facts and Figures. Retrieved December 9, 2022, from

Chen, H.-M., Tu, H.-M., & Ho, C.-I. (2013). Understanding biophilia leisure as facilitating well-being and the environment: An examination of participants’ attitudes toward horticultural activity. Leisure Sciences, 35(4), 301–319.

Cipriani, J., Benz, A., Holmgren, A., Kinter, D., McGarry, J., & Rufino, G. (2017). A systematic review of the effects of horticultural therapy on persons with mental health conditions. Occupational Therapy in Mental Health, 33(1), 47–69.

Clatworthy, J., Hinds, J., & M. Camic, P. (2013). Gardening as a mental health intervention: A Review. Mental Health Review Journal, 18(4), 214–225.

Han, A.-R., Park, S.-A., & Ahn, B.-E. (2018). Reduced stress and improved physical functional ability in elderly with mental health problems following a horticultural therapy program. Complementary Therapies in Medicine, 38, 19–23.

Horticultural Therapy Institute. (2022). Horticultural therapy careers. Horticultural Therapy Institute: Linking people and plants. Retrieved Retrieved December 9, 2022, from

Kam, M. C. Y., & Siu, A. M. H. (2010). Evaluation of a horticultural activity programme for persons with psychiatric illness. Hong Kong Journal of Occupational Therapy, 20(2), 80–86.

Kenmochi, T., Kenmochi, A., & Hoshiyama, M. (2019). Effects of horti- cultural therapy on symptoms and future perspective of patients with schizophrenia in the chronic stage. Journal of Therapeutic Horticulture, 29(1).

Kontos, K., Koutsou, S., Sismanidi, A., Theodoropoulou, N., Nikolopoulou, V., Filippiadou, M., & Papazisis, G. (2021). The effects of horticultural therapy on the functionality of psychotic patients employed in the green unit of the Psychiatric Hospital of Thessaloniki Greece. European Psychiatry, 64(S1).

Lin, Y., Lin, R., Liu, W., & Wu, W. (2021). Effectiveness of horticultural therapy on physical functioning and psychological health outcomes for older adults: A systematic review and meta‐analysis. Journal of Clinical Nursing, 31(15-16), 2087–2099.

Marcus, C. C., & Barnes, M. (1999). Healing gardens: Therapeutic benefits and design recommendations. J. Wiley.

Ng, T. K., Gan, D. R. Y., Mahendran, R., Kua, E. H., & Ho, R. C.-M. (2021). Social connectedness as a mediator for horticultural therapy's biological effect on community-dwelling older adults: Secondary analyses of a randomized controlled trial. Social Science & Medicine, 284, 114191.

Nicholas, S. O., Giang, A. T., & Yap, P. L. K. (2019). The effectiveness of horticultural therapy on older adults: A systematic review. Journal of the American Medical Directors Association, 20(10).

NursingBird. (2022, March 7). Social Work in Mental Health in Canada. Retrieved December 9, 2022, from

Santomauro, D. F., Mantilla Herrera, A. M., Shadid, J., Zheng, P., Ashbaugh, C., Pigott, D. M., Abbafati, C., Adolph, C., Amlag, J. O., Aravkin, A. Y., Bang-Jensen, B. L., Bertolacci, G. J., Bloom, S. S., Castellano, R., Castro, E., Chakrabarti, S., Chattopadhyay, J., Cogen, R. M., Collins, J. K., … Ferrari, A. J. (2021). Global prevalence and burden of depressive and anxiety disorders in 204 countries and territories in 2020 due to the COVID-19 pandemic. The Lancet, 398(10312), 1700–1712.

Siu, A. M. H., Kam, M., & Mok, I. (2020). Horticultural therapy program for people with mental illness: A mixed-method evaluation. International Journal of Environmental Research and Public Health, 17(3), 711.

Siu, A. M. H., Kam, M., & Mok, I. (2020). Horticultural therapy program for people with mental illness: A mixed-method evaluation. International Journal of Environmental Research and Public Health, 17(3), 711.

Smetanin, P., Stiff, D., Briante, C., Adair, C.E., Ahmad, S. &  Khan, M. (2011). The Life and Economic Impact of Major Mental Illnesses in Canada: 2011 to 2041. RiskAnalytica, on behalf of the Mental Health Commission of Canada 2011.

Söderback, I., Söderström, M., & Schälander, E. (2004). Horticultural therapy: The ‘healing garden’and gardening in rehabilitation measures at Danderyd Hospital Rehabilitation Clinic, Sweden. Pediatric Rehabilitation, 7(4), 245–260.

Tu, H. M. (2022). Effect of horticultural therapy on Mental Health: A meta‐analysis of Randomized Controlled Trials. Journal of Psychiatric and Mental Health Nursing, 29(4), 603–615.

World Health Organization. (2022). World mental health report: transforming mental health for all. ISBN 978-92-4-004933-8

Zhu, S., Wan, H., Lu, Z., Wu, H., Zhang, Q., Qian, X., & Ye, C. (2016). Treatment Effect of Antipsychotics in Combination with Horticultural Therapy on Patients with Schizophrenia: A Randomized, Double-blind, Placebo-controlled Study. Shanghai archives of psychiatry, 28(4), 195–203.

Some rights reserved
Permission is granted to copy, distribute and/or modify this document according to the terms in Creative Commons License, Attribution-NonCommercial 4.0 International . The full text of this license may be found here: CC by-nc 4.0