||Optimal management strategies for herbaceous biomass production depend on the interaction of crop and environmental resources and the resulting yield patterns through time. The objectives of this study were to determine the production potential of different perennial herbaceous biomass crops under several management regimes and to test regression analysis as a method for determining the effect of stand age on the production potential of these species on representative soils of the Eastern Great Lakes Region of the United States. Eastern gamagrass, flatpea, reed canarygrass, switchgrass, and mixtures of alfalfa-smooth bromegrass, timothy-redtop-red clover, and naturalized meadows were grown at three fertility levels under two cutting-management regimes for up to 5 years at various locations in New York State. Annual yields ranged from about 4 to more than 12 Mg ha-1, depending on species, soil, and crop management. Regression analyses revealed four patterns of change with time and provide a convenient method for modeling these crop yield patterns.