This study comprehensively evaluates the values, beliefs, knowledge, and environmental consciousness of students participating in the School Botany Program regarding plant genetics conservation. Thailand's rich biodiversity, including over 200,000 plant species, faces significant threats, necessitating conservation efforts. In response, the Plant Genetics Conservation Project (RSPG) was launched to promote sustainable conservation and development. Using a mixed-methods approach, Phase 1 involved qualitative case studies to build a hypothetical model by examining student-level and school-level determinants in selected schools. Phase 2 quantitatively validated this model across 52 schools (n = 2299). Results demonstrated that the Botanic Gardens in Schools Program significantly enhances student learning outcomes in moral, cognitive, and ecological domains. Qualitative findings highlighted innovative student projects fostering environmental stewardship, while quantitative analysis underscored a robust inclination towards pro-environmental actions. Model validation confirmed the theoretical framework's robustness, emphasizing the role of individual beliefs and innovative teaching practices in shaping environmental consciousness ([chi-squared]/df = 5.38, RMSEA = 0.04, CFI = 0.98, TLI = 0.94, SRMRW = 0.31, SRMRB = 0.07). This study offers valuable insights for enhancing environmental education policies and practices, suggesting that garden-based education fosters a deeper connection to nature, encourages sustainable behaviors, and supports the development of conservation mindsets among students.