The therapeutic values of plants

The article ‘Horticultural therapy: the ‘healing garden’ and gardening in rehabilitation. Measures at Danderydd Hospital Rehabilitation Clinic, Sweden’ by Soderstrom et al. in issue 7:4 of Pediatric Rehabilitation brings together a great deal of existing information and clearly illustrates the need for more research and professional publication in this field. A review of the literature is an integral part of the understanding of any therapeutic modality and over the years a number of literature reviews have been published or made available electronically [1–4]. However, these literature reviews have been broadbased and comprehensive collections of articles from many sources that are not easily available to the general public, thus giving the impression of a wider body of knowledge than is actually available to researchers in healthcare. The importance and advantage of the current article is that the authors focused primarily on medical databases (AMED, CINHAL, MEDLINE) and limited their search to the three terms that should be in common usage in any articles related to the therapeutic value and uses of horticulture and gardening: ‘gardening’, ‘healing garden’ and ‘horticultural therapy’. This choice of approach by the authors brought into clear focus the extremely limited information readily available to members of the medical professions and the need for high quality, rigorous research that can be published in peer-reviewed healthcare and medical journals. Perhaps the greatest hindrance to wider application of healing gardens and horticultural therapy in health care is the lack of documentation of the efficacy of these techniques utilizing medically acceptable research methods. As pointed out by Frumkin [5], for a long time medical practice ‘relied on some combination of inductive reasoning and seductive beliefs’. In a similar fashion, practitioners in horticultural therapy and users of healing gardens tend to write and lecture on their benefits without research-based documentation on the efficacy, in the mistaken belief that the benefits and efficacy are so obvious that further documentation is not required. However, as Frumkin elaborates regarding medicine, ‘in recent years, more and more treatments have been subjected to rigorous deductive study. The goal here is evidence-based medicine’ because ‘those who pay for health care—employers and insurance companies in the US, national health care systems in most other countries, and patients themselves in some places—don’t want to pay without evidence of value’. The same applies to the practice of horticultural therapy and implementation of healing gardens; it will not be paid for by anyone without strong evidence supporting its efficacy. Properly designed, randomized controlled trials can establish the value of an intervention. Exceptions to this research design have been used effectively in cases where randomized treatments occurred serendipitously, despite the fact that the variable being analysed was never part of the original plan of the treatment. The classic example of this type of posttreatment analysis taking advantage of years of clinical data resulting in meaningful research results, is the study by Ulrich [6], in which he reviewed the records over a 10-year period of cholecystectomy patients who were assigned at random to rooms facing either a stand of deciduous trees or a brown brick wall, based on room availability. By restricting his study to matched pairs of males in the hospital during summer months when the trees were in foliage, he was able to determine statistically significantly positive effects of the view of trees. A more recent study at Johns Hopkins University [7] used nature scenes and sounds as an intervention