GARDENING ACTIVITIES, STRESS, AND SOCIAL INTERACTION IN COLLEGE STUDENTS

Study Population

Study Population:

The study population consists of all actively enrolled students at Bingöl University Vocational School of Health Services (VSHS), Türkiye.

Sampling Method Participants will be recruited through voluntary announcements among eligible students. Sample size will be calculated using G\*Power version 3.1.9.7, based on previous campus-based horticultural intervention studies (Gigliotti et al., 2019), assuming a medium effect size (Cohen's d = 0.50), a significance level of 0.05, and 80% statistical power. Considering an anticipated dropout rate of approximately 20%, at least 100 students will be included (Intervention group = 50; Control group = 50).

Inclusion Criteria:

Being an actively enrolled student at Bingöl University Vocational School of Health Services.

Age between 18 and 25 years. Providing written informed consent. No chronic disease preventing participation in light outdoor physical activities.

No known allergy to pollen or soil.

Exclusion Criteria:

Missing more than 25% of the intervention sessions (absence from more than two sessions).

Initiating professional psychiatric or psychological treatment during the study period.

Outcome Measures Primary Outcome

Perceived Stress Scale (PSS-10) Perceived stress will be assessed using the Turkish version of the 10-item Perceived Stress Scale (PSS-10) originally developed by Cohen et al. (1983) and culturally adapted into Turkish by Erci (2006). Items are rated on a 5-point Likert scale ranging from 1 (Never) to 5 (Very Often). Total scores range from 10 to 50, with higher scores indicating greater perceived stress.

Secondary Outcomes

Peer Relationships Subscale of the University Life Scale:

Peer interaction and social connectedness will be evaluated using the Peer Relationships Subscale of the University Life Scale developed by Aladağ et al. (2012). The subscale contains eight items rated on a 7-point Likert scale (1 = Not at all appropriate to 7 = Completely appropriate). Higher scores indicate stronger peer relationships and social integration within the university environment.

Nature Relatedness Scale (Turkish Version):

Connection with nature will be measured using the Turkish adaptation of the Nature Relatedness Scale, originally developed by Mayer and Frantz (2004) and adapted by Bektaş et al. (2017). The Turkish version consists of eight items grouped into two subscales: Being Part of Nature (6 items) and Integration with Nature (2 items). Items are scored on a 5-point Likert scale from 1 (Strongly disagree) to 5 (Strongly agree). Higher scores indicate a stronger sense of connectedness to nature.

Intervention Description

Experimental Group:

Participants assigned to the intervention group will participate in a structured horticultural therapy program conducted in the garden of Bingöl University Vocational School of Health Services. The intervention will last 4 weeks, consisting of 8 sessions (two sessions per week), each lasting approximately 60-90 minutes.

Activities will follow horticultural therapy principles described by Relf (2006) and Detweiler et al. (2012) and include:

Site orientation and team formation Soil preparation and bed organization Planting seedlings and sowing seeds Watering and routine plant care Weeding and soil cultivation Plant maintenance and staking Landscape improvement activities Reflection, group discussion, and program closure

Throughout the intervention, collaborative teamwork, peer communication, shared responsibility, social interaction, and campus belonging will be emphasized.

Control Group:

Participants in the control group will continue their usual university life without receiving any structured horticultural intervention during the study period. After completion of the study, they will be offered an optional brief horticultural workshop for ethical considerations.

Data Collection

Data will be collected twice:

Baseline: One week before the intervention. Post-intervention: One week after completion of the 4-week program. Assessments will be conducted through face-to-face questionnaires administered by the researchers.

Statistical Analysis:

Data will be analyzed using IBM SPSS Statistics version 26.0. Normality will be assessed using the Shapiro-Wilk test together with skewness and kurtosis values. Baseline demographic homogeneity between groups will be evaluated using the Chi-square test. Depending on data distribution, within-group comparisons will be performed using the Paired Samples t-test or Wilcoxon Signed-Rank Test, whereas between-group comparisons will be analyzed using the Independent Samples t-test or Mann-Whitney U test. Statistical significance will be accepted at p \< 0.05.

Risk Management and Contingency Plan

Potential challenges and contingency strategies include:

Adverse Weather Conditions:

If outdoor activities cannot be conducted because of heavy rain or other unfavorable weather conditions, planned gardening sessions will be relocated indoors. Alternative activities such as container gardening, indoor plant care, seed sowing in pots, or terrarium construction will be implemented to maintain intervention continuity.

Participant Attrition:

To compensate for potential dropout, approximately 20% additional participants will be recruited beyond the minimum required sample size. Sessions will be scheduled according to students' availability, and refreshments together with participation certificates will be provided to encourage attendance.

Seasonal or Soil-Related Problems:

Climate-appropriate, fast-growing plant species (e.g., mint, basil, lettuce, or seasonal flowers) will be selected in consultation with agricultural specialists. If soil quality proves inadequate, commercial potting soil and organic fertilizer will be used to optimize growing conditions.

• Change in Peer Interaction and Social Adjustment [Time frame: Baseline (Pretest) and Immediately Post-Intervention at Week 4 (Posttest)]