The efficacy of biostimulants on turfgrass creeping bentgrass (A. stolonifera) were tested in lab and greenhouse growth conditions. Biostimulants with initial efficacy improving greenness and/or biomass in lab trials mainly improved the physiology of the plant. The novelty of this study is the exogenous foliar application of phycocyanin on turfgrass as well the evaluation of GABA, GB, and R. intraradices on different creeping bentgrass cultivars under non-stress conditions. However, biostimulants affected different parameters of turfgrasses affected by cultivar. Ilyonectria mors-panacis causes low levels of root rot of American ginseng (Panax quinquefolius) in non-replant soil, but high levels when ginseng is grown in previously planted soil with ginseng, which results in replant disease (Farh et al, 2018). This study clearly shows that post-harvest debris decay of ginseng introduces considerable material into soil that has at least short-term effects, such as those observed with soil bacterial populations.