Establishment of Native Grass and Forb Species on Georgia Roadsides.

Invasive species are a costly problem in the State of Georgia, and roadsides are particularly effective vectors in spreading such species. Establishment of native species on Georgia roadsides may prevent further spread of invasive species and weeds, while maintaining effective vegetation cover. Field studies were conducted in five different locations throughout the State of Georgia to determine the effects of seeding timing, seeding rate, species selection and irrigation on the establishment of grass and forb species native to the Southeastern United States. Preliminary analyses suggest that species selection is a highly significant factor in obtaining effective roadside establishment of natives. Species that exhibited emergence in the first spring after planting typically returned the following spring with greater cover, regardless of timing of seeding. Native grasses tended to be more sensitive to timing of seeding than forbs. Data also suggests that in areas with heavy warm-season weed pressure in the early-mid spring, native establishment is significantly hindered. Irrigation may further exacerbate this warm-season weed pressure. The effect of seeding rate was significant at the end of the first growing season, but showed no interaction with other factors in current analyses.