||Switchgrass is an erect warm-season (C4) perennial grass which was common on the plains of North America. It has been used for many years for pastures, re-seeding programs, and recently is being investigated as a possible source of biomass for use as alternative fuels. However, seed of native grasses can have low germination rates due to seed dormancy, and seedlings that do germinate are notoriously slow to establish. The objective of this work was to determine if sorghum-sudangrass could be planted in conjunction with switchgrass. First year biomass would come from the sorghum while the switchgrass established in the understory. The experiment, established under normal field conditions, consisted of a RCB design with four replications of four treatments (varying amounts of sorghum-sudangrass seed plus a fixed amount of switchgrass and switchgrass alone). Stand counts of both species were taken starting at 14 days after planting. Additional data taken included: sorghum-sudangrass stand count, switchgrass height, final switchgrass stand, and sorghum yield. After sixty days, the sorghum-sudangrass was harvested and final yields assessed. Statistical analysis showed no significant difference in sorghum yield among treatments of 16, 10, and 6 sorghum plants per meter row (5, 3, and 2 foot of row). Switchgrass height decreased with increasing density of sorghum stand. Switchgrass stand count decreased from 37 to 14 per 6.1 meters (20 ft) of row, with increasing sorghum population, however, successful stands of switchgrass have been reported with as few as 1 plant for every 0.6 meter (2 ft) of row. Persistence during winter and spring green-up will indicate if co-seeding is a viable option for switchgrass establishment, allowing producers to acquire a biomass crop from sorghum during the first year while switchgrass is establishing.