Concepts of plant water use, photosynthesis, and respiration have historically been challenging for undergraduates in introductory horticulture courses. To increase student understanding of these concepts, we conducted a study in a principles of horticultural science course with two lab sections and a total enrollment of 51 students. After traditional lectures of these plant physiological processes concluded, we used a flipped classroom approach with the learners as teachers to increase student learning. Each lab section was divided into six groups, with 12 groups in total. Groups were assigned one of the three topics and presented their topic to two other groups of students. Five knowledge-based questions on each physiological process, 15 questions total, were included on a pre-test prior to hearing lectures. The same 15 questions were given on a post-test following the lectures, but prior to the student presentations. Those 15 questions were also included on the unit exam following the presentations. No significant differences were found between pre-test and exam scores when evaluated for specific topics students presented. However, an 80% overall score increase from the pre-test to the unit exam was reported. This correlates with student responses to a post-survey in which 80% of the students indicated they understood the other physiological processes better after hearing the group presentations. Our results show that a flipped classroom approach of students teaching students can be effective at increasing student understanding of difficult horticultural concepts.
