Many public gardens offer tours to schoolchildren. Informal educators argue that preparing students for a field trip by providing pre- and post-visit activities can positively impact learning. However, there is little research that supports the efficacy of pre- and post-visit activities on learning at public gardens. Therefore, the purpose of this research was to determine the impact of pre- and post-visit activities on learning after a field trip to a public garden. This quasi-experimental study's population included four fifth-grade classrooms assigned to one of two treatments: 1) a field trip only (control) and 2) a field trip with pre- and post-visit activities (treatment). A post-trip assessment consisted of open-ended questions and was scored quantitatively. Differences between treatment groups were analyzed by using a t-test. Findings indicated that there was no significant difference in post-test scores between the treatment groups. Although pre- and post-visit activities have been found to prepare students for a field trip and to tie the field trip to classroom learning, this case study did not show an increase in learning outcomes. A limitation of this research was the small number of students involved and should be conducted again with more students. However, the novel method of analysis may have implications for assessing what students learn on field trips to informal settings. This research has implications for informal education settings such as public gardens, botanical centers, and arboreta that seek to measure visitor learning.