Understanding valuation of and access to traditional agroecological knowledge (TAeK) in industrialized countries is key to designing initiatives that can reverse the erosion of TAeK. We explored these issues using a quasi-experimental design. We measured valuation and access to TAeK with a survey before and after an intervention based on a citizen science school program. The participants were Catalan agricultural technical students (N = 173), i.e., rural youth with an interest in agriculture and natural resources. We found that the study population values TAeK quite highly and accesses it relatively frequently outside the classroom. Moreover, the intervention, together with hands-on activities such as home gardening, had a positive effect on how much and how often students valued and accessed TAeK. Education programs such as the one presented here could become allies in agroecological transitions that require TAeK to be accessible and valued by future farmers.