Giant miscanthus has the potential to move beyond cultivated fields and invade non-crop areas, but this can be overshadowed by aesthetic appeal and monetary value as a biofuel crop. Most research on giant miscanthus has focused on herbicide tolerance for establishment and production, rather than terminating an existing stand. This study was conducted to evaluate herbicide options for control or terminating a stand of giant miscanthus. In 2013 and 2014, field experiments were conducted on established stands of the giant miscanthus cultivars ‘Nagara’ and ‘Freedom’. Herbicides evaluated both years included glyphosate, hexazinone, imazapic, imazapyr, clethodim, fluazifop, and glyphosate + fluazifop. All treatments were applied in summer (June or July) and September. For both years, biomass reduction ranged from 85 to 100% when glyphosate was applied June/July at 4.5 or 7.3 kg ae ha-1. No other treatment applied at this timing provided more than 50% giant miscanthus biomass reduction one year after application. September applications of glyphosate were not consistent, with treatments in 2013 reducing biomass by 40% or less, while in 2014 at all rates provided ≥78% biomass reduction. Glyphosate applications in June/July was the only treatment to provide effective and consistent control of giant miscanthus one year after treatment.