Invasive species such as Lespedeza cuneata (sericea) can have detrimental effects on invaded ecosystems. One proposed explanation for invasive success such as sericea is production of allelopathic chemicals that suppress adjacent native species. We tested this hypothesis in a greenhouse experiment in which a native grass was grown with sericea and alone. Three different treatments were factored among the pots. These treatments include different soil histories, autoclaving the soil, and an extract made from mature sericea. After twelve weeks plants were collected, dried and biomass recorded. Results indicated that the soil history has an effect on sericea biomass. This suggests that sericea may be able to change the soil microbial communities over time, leading to long-term negative effects on surrounding native plants.