The use of residual biomass for the production of bioenergy and biomaterials is often suggested as a strategy to avoid negative effects associated with dedicated biomass production. One potential source is biomass from landscape management. The goal of this study was to find the lowest net greenhouse gas (GHG) emissions of various applications of residual biomass from landscape management. GHG balances of thirteen residual biomass applications were calculated and compared to their respective conventional counterfactuals. As a case study, the potential contribution to climate change mitigation through the use of residual biomass available from vegetation management in floodplains of the Dutch Rhine delta were quantified. The greatest GHG benefits are achieved when using woody biomass to produce heat (−132 kg CO 2 -eq./tonne wet biomass) and grassy biomass to produce growth media (−229 kg CO 2 -eq./tonne wet biomass). In contrast, composting grassy biomass for fertiliser replacement on agricultural fields results in the largest GHG burdens of 62 kg CO 2 -eq./tonne wet biomass. The findings imply that residual biomass from landscape management can contribute to both GHG benefits and burdens, depending on the application. Higher benefits were found for bioenergy than for biomaterial applications. Biomass applications should be chosen with care and consideration of their counterfactuals.