Connecting college students with nature: An evaluation indicator system for the implementation of horticultural therapy programmes on university campuses

Based on the analysis and summary of horticultural therapy-related research and the components, an evaluation system for the implementation of campus horticultural therapy programmes was preliminarily constructed. There are four first-level indicators and ten second-level indicators in the system (Table 1). The Delphi method would be used to evaluate and modify the initial evaluation system and to determine the final evaluation indicator system.

Delphi survey is a feedback anonymous inquiry method. The process is as follows: after obtaining the opinion of the expert on the issue to be predicted, the opinion is collated and summarised, after which it is fed back to the expert anonymously, and the opinion is again collated and summarised, and feedback is given, until a consensus opinion is obtained (Campos-Luna et al., 2019). The steps in the Delphi method that this study used are as follows.

In the Delphi method, the following three aspects are used to assess the reliability of the expert evaluation results.

AHP developed by Saaty (1977) was used to calculate the weights of the indicators. Based on human experience and knowledge, it uses pairwise comparison to generate relative magnitudes (Martín-Fernández et al., 2018). The weight of each indicator in the hierarchy system can be calculated following experts’ comparisons and consistency test (Zhuang et al., 2022). Combined with the Yaahp software (version 11.0, Shanxi Meta Decision Software Technology Co., Taiyuan, China), the AHP method used in this study involves the following steps.

Selection of evaluators

Considering that the target of horticultural therapy programmes in this study is college students, in order to gain a deeper understanding of their perspectives, on the basis of inviting 10 experts of the Delphi method (Table 2), college students are also included as evaluators for weight evaluation. The college student evaluators were from the School of Architecture, Harbin Institute of Technology. The school has majors related to Landscape architecture and Environmental design. Moreover, two teachers have obtained the certification of HTRs in the United States and reasonably guided horticultural activities, so the school has a base of student involvement and experience in conducting horticultural activities.

The school is located in Harbin (44°04′-46°40′N, 125°42′-130°10′E), a city in northeast China. The city has a temperate continental monsoon climate and endures prolonged winters spanning up to 5 months, typically from November through March. In January, the average minimum temperature drops to -25°C (Zhao et al., 2024). Depending on the climatic conditions, campus horticultural activities are carried out from April to October each year. These gardening activities are open to college students of all health conditions. From April to June, college students carry out horticultural planting activities in the campus green space (due to the limitation of the size of the site and activity funds, most of the plants planted are herbaceous plants and small shrubs) (Figures 1 and 2), and post-maintenance is carried out in the period of July to October. In November 2023, 40 college students who participated in horticultural activities in that year were randomly selected to evaluate the weights.

Figure 1.

Figure 2.

The effective response rates of the two rounds of expert consultation were both 100%, indicating that the experts were enthusiastic in the research. In terms of the authority of experts (Table 6), the mean value of authority coefficient (Cr) for the four first-level indicators in the two rounds of consultation ranges from 0.795 to 0.905, and the authority of experts is high. In terms of the degree of expert opinions’ coordination degree (Table 7), the Kendall coordination coefficient W in the results of the first round of consultation is small, at only 0.228, reflecting that there are differences in the experts’ understanding of the importance of the evaluation indicators and the degree of coordination of their opinions is low. The Kendall coordination coefficient W of the second round of consultation has improved considerably compared with the first round, at 0.442, indicating that the experts’ understanding of the importance of the indicators is gradually converging, and the degree of credibility is high. The p-value corresponding to Kendall’s W of the two rounds are both <0.05, which is statistically significant, indicating that the experts’ assessment opinions are well coordinated, and the results are desirable.

After the first round of Delphi consulting, the mean importance values of the indicators in the initial evaluation system (Table 1) were all >4, and the CV values were all <0.25, and all 10 experts believed that the indicators in the initial evaluation system did not need to be deleted. Under the first-level indicator of post-maintenance management, two experts proposed that the operation and maintenance team could be added as a second-level indicator, while three experts proposed that project cost control could be added as a second-level indicator. Taking into account the experts’ comments, two second-level indicators were added to the original evaluation system. The revised evaluation system contains 4 first-level indicators and 12 second-level indicators. A second round of Delphi consultation was conducted, and the statistical results showed that the mean importance values of all indicators was >4, and the CV values were all <0.25. Ten experts agreed that the evaluation system was reasonable, and that there was no need to add, delete or modify the indicators.

A two-round Delphi method was used to build the evaluation system for the implementation of horticultural therapy programmes on university campuses (Figure 3). The system includes 4 indicators in the criteria layer and 12 indicators in the indicator layer (Table 8). Conducting a horticultural therapy programme on a college campus requires consideration of four aspects: the horticultural therapy team, the horticultural therapy plan, the natural healing environment and post-maintenance management.

Figure 3.

The horticultural therapy team consists of two components: a horticultural professional guidance team and a horticultural volunteer team. The horticultural professional guidance team can be composed of experts from different disciplines and professions, such as medicine, psychology, landscape architecture and horticulture, to ensure complementarity of knowledge and to maximise the experience of different fields for treatment and rehabilitation programmes. The horticultural volunteer team is mainly composed of college students majoring in Landscape architecture, Medicine and other related majors or trained members of horticulture-related student societies. They mainly assist the horticultural professional guidance team in the planning and organisation of horticultural therapy programmes, and undertake the publicity, operation and maintenance of some horticultural therapy programmes, which plays an important role in the promotion of horticultural therapy on campus (Anderson et al., 2018). In addition, the team mainly comes from colleges, and they understand college students’ horticultural activity needs and preferences, which is more helpful for the implementation of horticultural therapy programmes on university campuses.

Generally speaking, the horticultural therapy plan includes three parts: the therapeutic schedule, the planning of horticultural activities and the treatment effectiveness evaluation. Setting a therapeutic schedule on a college campus requires a combination of factors such as the college participants’ spare time arrangement, health status, recovery goals and the healing techniques available on campus. Horticultural activities are carried out in a green growing environment with good interaction with nature, which is conducive to facilitating better communication and cooperation between therapists and patients, reducing or eliminating resistance in the traditional psychotherapy process, improving public participation, facilitating teamwork and unconsciously increasing the participants’ social connection. Horticultural activities that can be easily carried out on university campuses generally include plant growing, landscaping and so on (Zhong and Tu, 2020). These activities each have their own corresponding goals, such as physical endurance enhancement, improvement in hand–brain coordination, emotional regulation and creativity stimulation. The treatment effectiveness evaluation is to evaluate the effectiveness of horticultural treatment through the recording of individual physiological and psychological health information and the recording of the treatment process with the help of qualitative and quantitative research techniques, so as to facilitate the adjustment and improvement of the horticultural therapy plan at a later stage.

Natural healing environment includes horticultural space, healing landscapes and horticultural facilities. The first step in creating a natural healing environment is to select and design a horticultural site, which can be an open green space or garden on campus, or an indoor environment such as a flower house or greenhouse. Second, there is a need for healing landscape design. The design of the landscape form of healing environment should not only fully reflect the beauty and vitality of nature, but also adapt to the implementation of various nature-related healing activities. Third, the healing environment needs to be planned and set up with appropriate horticultural facilities to ensure the normal conduct of horticultural activities. Horticultural facilities on the university campus mainly include raised planting beds, trellises, water supply and drainage facilities.

The post-maintenance management needs to be considered in terms of landscape maintenance, horticultural resource management, operation and maintenance team and project cost control. First, attention needs to be paid to the overall environment of the horticultural site, with regular cleaning of the site, maintenance of plants and updating of facilities to maintain the healing effect of the landscape. The management of horticultural resources in the site is also indispensable, such as the management of pests and diseases, renovation of the soil and storage of seeds, which are guarantees for the sustainability of horticultural activities (Shi et al., 2019). The operation and maintenance of the entire horticultural therapy programme relying on horticultural professional guidance teams and volunteer teams is not enough and can be complemented by the operation and maintenance management team (Ding et al., 2020). The operation and maintenance team are mainly composed of relevant functional departments of the school (e.g. university Logistics Department), which can promote the sustainability of the horticultural therapy programme with its advantages in management and coordination. In addition, the cost of the programme needs to be reasonably controlled to facilitate continuity.

A weight analysis of the evaluation system (Table 8) using AHP revealed that the horticultural therapy plan (0.341) was most important in the criteria layer, followed by the natural healing environment (0.289), the horticultural therapy team (0.190) and post-maintenance management (0.180). Horticultural activity was the most heavily weighted among the 12 indicators in the indicator layer (0.151), and the detailed information is shown in Table 9.

According to Table 10, the CR values of indicators in the criteria and indicator layers were all <0.1, demonstrating the high consistency of the expert judgement matrix and the rationality of the hierarchical model.

As illustrated in Figure 3, implementation of a horticultural therapy programme on a university campus necessitates the consideration of four key aspects: the horticultural therapy team, the horticultural therapy plan, the natural healing environment and post-maintenance management. These four aspects collectively constitute the complete process of implementing a horticultural therapy programme (Figure 4).

Figure 4.

First, for a horticultural therapy team, the combination weights of its two second-level indicators rank third and seventh, respectively, with some importance (Table 9). As a natural intervention closely related to evidence-based medicine and psychotherapeutic techniques, the formation of a horticultural therapy team is the foundation for implementation of a horticultural therapy programme and a guarantee for the promotion of professionalism and continuity of therapeutic activities (Davis, 2011). The horticultural therapy team connects the college students to the therapeutic activities and determines the process and quality of the therapeutic programme. This is the most creative and flexible part of the horticultural therapy programmes, just as the doctor’s expertise somewhat determines the outcome of the patient’s recovery. For this reason, the training and assessment of horticultural therapists is extremely rigorous in many countries around the world. In the United States, in occupations related to human health, such as healthcare, practitioners are required to adhere to strict industry standards and conduct professional training. In horticultural therapy as a part of the healthcare system, therapists should obtain basic professional qualifications in order to carry out health-related medical activities (Starling et al., 2014). Since horticultural therapy started late in China, there is currently no professional recognition for horticultural therapists. Therefore, instructors and students with an academic background or practical experience related to horticultural therapy are particularly important on Chinese university campuses.

Second, for the horticultural therapy plan, its weight (0.341) is the largest among the four criteria layer indicators, representing the highest importance (Table 9). The horticultural therapy plan is the core of the entire horticultural therapy programme, which includes an analysis of the health problems and needs of a particular population or each client, as well as a schedule of horticultural plantings and other therapeutic activities based on psychotherapeutic techniques, healing theories and the characteristics of the healing environment. Among the 12 indicators in the indicator layer, the combination weight of therapeutic schedule is 0.132, ranking second and having high importance (Table 9). Numerous studies have shown that the therapeutic schedule for the service population and clients is the most critical element in the implementation of horticultural therapy (Detweiler and Warf, 2005; Kim et al., 2014), which reflects both the science of evidence-based medicine and the unique advantages of horticultural therapy in natural interventions. This is the fundamental difference between horticultural therapy and traditional medical methods. It is also worth noting that horticultural activity had the largest combination weight of 0.151 and therefore is of the highest importance. The importance of horticultural activities was similarly affirmed in the study by Liu and Ma (2021), who argued that the core of horticultural therapy is mainly embodied in horticultural activities, which give individuals with participatory horticultural landscape forms to reduce stress and fully reflect the interaction between people and plants. In addition, as a health service tool, the treatment effectiveness evaluation in horticultural therapy programmes is an essential part (Yang et al., 2022).

Third, for natural healing environment, its weight is 0.289, which is the second most important. (Table 9). Horticultural therapy is a natural intervention based on active horticultural practices, and often utilises passive landscape experiences to achieve physical and psychological recovery (Scartazza et al., 2020). As the spatial carrier and medium of passive sensory experience and active horticultural practice, the natural healing environment and horticultural therapy are inseparable.

Finally, post-maintenance management is necessary. Horticultural therapy programmes are often not one-time events and require participants to bond over long-term interactions with plants. Studies have also shown that long-term participation in gardening may be better for the psychological health of college students (Guo et al., 2023). Therefore, in order to ensure that the horticultural therapy programme on college campuses can be carried out in a sustainable manner, and to promote the health benefits of horticultural therapy to continue to act on college students, the management and maintenance of the later stage is necessary. This determines, to some extent, whether college students will participate in horticultural therapy programmes in the long term. Among the four second-level indicators of post-maintenance management, the operation and maintenance team has the largest weight of 0.404 and is of the highest importance (Table 9). Management and maintenance require the coordination of multiple parties, including horticultural therapists, horticultural therapy participants, university student volunteers and relevant school functions, to carry out a number of tasks, including management team formation, landscape maintenance, horticultural resource management and programme cost control. At the same time, residents around the campus can be organised to promote community participation to expand the social benefits of the campus horticultural therapy programme while maintaining the horticultural therapy programme and serving public health (Suto et al., 2021). In conjunction with the maintenance needs of the horticultural therapy programme, a number of spontaneous public welfare activities and volunteer services by community residents are also important means of controlling the programme costs.