Definitions and Positions


Over the past decade many people have become aware of the positive benefits of human interaction with plants and gardens. The recent surge of interest in this relationship in combination with a great increase of horticultural activities in treatment programs have led to the use of numerous terms for these programs and activities such as therapeutic horticulture, garden therapy, social horticulture, and therapeutic gardening to name a few. Because these terms are used interchangeably it is difficult to distinguish one from another and horticultural therapy has often been used as the catch-all phrase. There are in fact some crucial differences between terms.

Likewise, gardens designed to support people-plant interactions and human well-being have been referred to as healing gardens, therapeutic gardens, and restorative gardens, among others. There are, however, some essential differences among garden types that can provide clarity to their design and purpose. To increase understanding of the profession, the American Horticultural Therapy Association (AHTA) has put together the following outline to define the terms recognized by AHTA that are associated with people-plant relationships and to provide additional information on horticultural therapy.

Types of Programs

Horticultural Therapy

Horticultural therapy is the engagement of a client in horticultural activities facilitated by a trained therapist to achieve specific and documented treatment goals. AHTA believes that horticultural therapy is an active process which occurs in the context of an established treatment plan where the process itself is considered the therapeutic activity rather than the end product. Horticultural therapy programs can be found in a wide variety of healthcare, rehabilitative, and residential settings.

Therapeutic Horticulture

Therapeutic horticulture is a process that uses plants and plant-related activities through which participants strive to improve their well-being through active or passive involvement. In a therapeutic horticulture program, goals are not clinically defined and documented but the leader will have training in the use of horticulture as a medium for human well-being. This type of program may be found in a wide variety of healthcare, rehabilitative, and residential settings.

Social Horticulture

Social horticulture, sometimes referred to as community horticulture, is a leisure or recreational activity related to plants and gardening. No treatment goals are defined, no therapist is present, and the focus is on social interaction and horticulture activities. A typical community garden or garden club is a good example of a social horticulture setting.

Vocational Horticulture

A vocational horticulture program, which is often a major component of a horticultural therapy program, focuses on providing training that enables individuals to work in the horticulture industry professionally, either independently or semi-independently. These individuals may or may not have some type of disability. Vocational horticultural programs may be found in schools, residential facilities, or rehabilitation facilities, among others.

Types of Gardens

Healing Gardens

Healing gardens are plant dominated environments including green plants, flowers, water, and other aspects of nature. They are generally associated with hospitals and other healthcare settings, designated as healing gardens by the facility, accessible to all, and designed to have beneficial effects on most users. A healing garden is designed as a retreat and a place of respite for clients, visitors, and staff and to be used at their desire. Healing gardens may be further divided into specific types of gardens including therapeutic gardens, horticultural therapy gardens, and restorative gardens. These garden types are likely to have overlap and the following definitions should be regarded as guidelines since no two gardens are the same.

Therapeutic Gardens

A therapeutic garden is designed for use as a component of a treatment program such as occupational therapy, physical therapy, or horticultural therapy programs and can be considered as a subcategory of a healing garden. A garden can be described as being therapeutic in nature when it has been designed to meet the needs of a specific user or population. It is designed to accommodate client treatment goals and may provide for both horticultural and non-horticultural activities. It should be designed as part of a multi-disciplinary collaborative process by a team of professionals. A therapeutic garden may exist on its own as an extension of an indoor therapeutic program area or it may be part of a larger healing garden.

Horticultural Therapy Gardens

A horticultural therapy garden is a type of therapeutic garden; it is designed to accommodate client treatment goals, but it is designed to support primarily horticultural activities. A horticultural therapy garden is also designed in such a manner that the clients themselves are able to take care of plant material in the garden.

Restorative Gardens

A restoration or meditation garden may be a public or private garden that is not necessarily associated with a healthcare setting. This type of garden employs the restorative value of nature to provide an environment conducive to mental repose, stress-reduction, emotional recovery, and the enhancement of mental and physical energy. The design of a restorative garden focuses on the psychological, physical, and social needs of the

Prevalence of Horticultural Therapy Programs and Healing Gardens

At this time horticultural therapy programs are not required to be registered or associated with any type of professional regulating body so it is difficult to say with precision how many programs are offered across the country or what types of programs are offered. The number of horticultural therapy and therapeutic horticulture programs has clearly increased over the past decade. Similarly, there is currently no comprehensive list of existing healing gardens. However, healing gardens are regularly featured in local and national publications and are being built with increasing frequency in a variety of settings. As awareness grows of the role these gardens play in effecting positive outcomes, people are requesting the creation of these types of gardens on an increasing basis. In the early 1990’s, there were few examples. Today, examples exist in most cities in public and private settings. AHTA developed the first therapeutic garden characteristics in 1995 and awarded the first Therapeutic Garden Design Award in 1997. AHTA has collaborated with the American Society of Landscape Architects (ASLA) on the development of healing gardens across the country.

Benefits of Horticultural Therapy and Therapeutic Gardens

The benefits of involvement in horticultural activities and exposure to nature can be seen in cognitive, psychological, social, and physical realms and research continues to reveal these connections across many groups of people. The following list includes some of the benefits that have been cited in the literature. Please note that many of these studies report on specific populations and the benefits may or may not be applicable to all groups.

Cognitive Benefits

  • Enhance cognitive functioning (Kaplan & Kaplan, 1989; Cimprich, 1993; Herzog, Black, Fountaine & Knotts, 1997)
  • Improve concentration (Wells, 2000; Taylor et al., 2001)
  • Stimulate memory (Namazi & Haynes, 1994).
  • Improve goal achievement (Willets & Sperling, 1983).
  • Improve attentional capacity (Hartig, Mang & Evans, 1991; Ulrich et al., 1991; Ulrich & Parsons 1992; Ulrich, 1999; Taylor et al., 2001)

Psychological Benefits

  • Improve quality of life (Willets & Sperling, 1983; Waliczek et al., 1996)
  • Increase self-esteem (Moore, 1989; Blair et al., 1991; Smith & Aldous, 1994; Feenstra et al., 1999; Pothukuchi & Bickes, 2001)
  • Improve sense of well-being (Relf et al.1992; Ulrich & Parsons, 1992; Galindo & Rodrieguez, 2000; Kaplan, 2001; Jarrott, Kwack & Relf, 2002; Barnicle & Stoelzle Midden 2003; Hartig, 2003)
  • Reduce stress (Ulrich & Parsons, 1992; Whitehouse et al., 2001; Rodiek, 2002)
  • Improve mood (Wichrowski, Whiteson, Haas, Mola & Rey, 2005; Whitehouse et al., 2001)
  • Decrease anxiety (Mooney & Milstein, 1994)
  • Alleviate depression (Relf, 1978; Mooney & Milstein, 1994; Cooper Marcus & Barnes, 1999)
  • Increase sense of control (Relf et al., 1992)
  • Improve sense of personal worth (Smith & Aldous, 1994)
  • Increase feelings of calm and relaxation (Moore, 1989; Relf et al., 1992)
  • Increase sense of stability (Blair et al., 1991; Feenstra et al., 1999; Pothukuchi & Bickes, 2001)
  • Improve personal satisfaction (Blair et al., 1991; Smith & Aldous, 1994; Feenstra et al., 1999; Pothukuchi & Bickes, 2001)
  • Increase sense of pride and accomplishment (Hill & Relf, 1982; Matsuo, 1995)

Social Benefits

  • Improve social integration (Kweon, Sullivan & Wiley, 1998)
  • Increase social interaction (Langer & Rodin, 1976; Moore, 1989; Perrins-Margalis, Rugletic, Schepis, Stepanski, & Walsh 2000).
  • Provide for healthier patterns of social functioning (Langer & Rodin, 1976; Kuo, Barcaicoa & Sullivan, 1998)
  • Improved group cohesiveness (Bunn, 1986)

Physical Benefits

  • Improve immune response (Hartig, Mang & Evans, 1991; Ulrich et al., 1991; Ulrich & Parsons 1992; Ulrich, 1999)
  • Decrease stress (Rodiek, 2002)
  • Decrease heart rate (Wichrowski, Whiteson, Haas, Mola & Rey, 2005)
  • Promote physical health (Ulrich & Parsons, 1992; Kweon, Sullivan & Wiley, 1998; Cooper Marcus & Barnes, 1999; Armstrong, 2000; Rodiek, 2002)
  • Improve fine and gross motor skills and eye-hand coordination (Moore, 1989)