Whole-process garden-making practice integrates site investigation, design development, construction, and post-construction maintenance into a continuous course sequence, providing an authentic context for developing students’ professional competence and comprehensive abilities. This study analyzed approximately 19,000 Chinese characters of reflective reports produced by 28 landscape architecture undergraduates. Following a procedural grounded theory approach, the reports were examined through open, axial, and selective coding. The analysis yielded 67 initial concepts, 22 subcategories, and five main categories, which were integrated into a theoretical model of educational value generation. The identified values comprised improved practical competence, reconstructed professional understanding, teamwork competence, comprehensive personal qualities, and enriched emotional and psychological experiences. Educational value developed as authentic tasks exposed practical problems, collaborative problem-solving supported cognitive adjustment, and repeated action and reflection fostered broader competencies. Project outcomes and maintenance experiences further strengthened students’ sense of achievement, belonging, and value recognition. This pathway of practice-driven engagement, cognitive development, capability formation, and emotional internalization provides a reference for the design of practice-based courses in landscape architecture and related disciplines.