In the past, NCDOT has used a combination of chemical and mechanical weed control management strategies that have proven time consuming and expensive to implement under and around over 1000 miles of median rail. NCDOT spent about $40 million in fiscal year 2019 for mowing. Zoysiagrasses are known to be a thick sod-producing turfgrass that once adequately established have minimal weed invasion. Zoysiagrass germplasm that can be established quicker using sprigging methods may provide a solution to their establishment and long-term maintenance. Thus, this project was conducted to evaluate different varieties, methods, timings, and companion crops for establishment of zoysiagrass on roadside plots. These evaluations were done on roadsides in different climatic regions of NC. For one objective, cultivars were seeded or sprigged at different timings (fall or spring) in “operational-sized” roadside plots. Zoysiagrass planted via seed was faster to establish with greater coverage for both locations and all timings compared to sprigging. Although establishment and coverage from sprigging material was not rapid, it should be noted that ‘El Toro’ zoysiagrass sprigs were able to show comparatively similar coverage to seed plantings after about 22 months. A secondary objective was to evaluate fall and spring zoysiagrass establishment using seed or sprigs with companion crops (wildlife mix, brown top millet, or none). Companion crops showed promise in sandy soils but did not increase zoysiagrass establishment in loamy soils. Overall, results from this research suggest that zoysiagrass seed or sprigs can be established on NC roadsides with minimal inputs but additional research is needed to refine the methods to increase establishment success and zoysiagrass cover. Additionally, progress was made in developing new vegetative zoysiagrasses with improved expansion rates and persistence under no inputs as wells as new populations with increased seed yields. Further evaluation of these newly bred materials is needed to confirm their suitability for roadside applications.
