School-based growing spaces support student engagement in science, technology, engineering, and mathematics (STEM) learning through authentic agricultural pursuits. We conducted a survey of Nebraska schools to characterize existing school-based growing spaces and to identify challenges limiting garden-based STEM learning. Our findings confirm the use of school-based growing spaces for kindergarten through 12th-grade STEM instruction, especially in the sciences. Opportunities for technology and engineering experiences are currently limited, and additional professional development support is needed to broaden garden-based STEM learning efforts. Our findings are relevant to current and future Extension efforts supporting school gardens, especially in rural agricultural communities.