To reach the cellulosic biofuel mandate set for 2022 in the US, perennial grasses, such as Giant Miscanthus and the newly introduced “Liberty” switchgrass, are expected to play a significant role as a promising feedstock for cellulosic ethanol. These grasses can grow well in the many parts of the U.S., especially in areas with ample rainfall. Miscanthus and switchgrass can adapt well to marginal land, which implies significant potential for marginal land currently under crop or forage production, and land currently enrolled in the Conservation Reserve Program to be converted into future commercial-scale biomass production.