High tunnels are a low-cost technology that can strengthen local and regional food systems by facilitating the production of high-quality fruits and vegetables during and beyond the frost-free growing season. The potential for high tunnels to improve crop quality and yield has been established with research trials, but there is a lack of research on the farm-level impacts of high tunnels, or comparisons between organic and conventional farming systems. This survey of high tunnel users in the U.S. Midwest state of Indiana finds that farmers have been successful with extending the growing season, as nearly half of the respondents are now harvesting in the cooler months and planting earlier in the spring. Farmers also reported significant increases in the productivity and quality of their crops year-round, and improvement in their farm’s economic stability. Farm-level impacts were similar for farmers using organic and conventional farming practices, although farmers using organic practices were more likely to increase their off-season production than their conventional counterparts. Overall, high tunnels hold potential as a tool for increasing the availability of fresh vegetables and fruits for local food systems, thus increasing the viability of Midwest farms.