As a response to the debate about the worth of completing a degree, higher education has built a set of assessment practices intended to quantify the change in a student as they matriculate from a first year to a graduate controlling for the different backgrounds of students. Cultural institutions like museums, zoos, aquariums, and public gardens face similar questions about the value they bring to their communities, and traditionally have relied on attendance-based data as a matter of convenience that falls well short of demonstrating impact as an informal learning setting. This study suggests higher education’s assessment practices can be used in the informal setting of an arboretum to quantify the impact engaging with one of its informal education programs has with participants.