Vegetation　has　been　found　to　improve　the　hydrological　performance　of　landfill　cover.　However,　existing　studies　ignore　effects　of　hydrogen　sulphide　(H2S),　which　is　a　toxic　odour　generated　from　municipal　solid　wastes.　H2S　is　a　potential　signalling　molecule　in　regulating　plant-stomata　aperture,　but　how　the　plant-H2S　interaction　affects　the　water-gas　transport　in　soil　remains　unknown.　This　study　aimed　to　investigate　effects　of　H2S　on　Bermuda　grass　growth　and　its　influence　on　water-gas　transport　in　unsaturated　soils.　Soil　columns,　with　and　without　vegetation,　were　prepared　and　fumigated　with　different　H2S　concentrations.　These　columns　were　subjected　to　controlled　drought　and　rainfall　sequentially.　The　results　showed　that　grass　leaves　almost　wilted　without　H2S　fumigation　due　to　the　Pythium　diseases　caused　by　antecedent　waterlogged　conditions.　In　contrast,　H2S　fumigation　promoted　grass　growth　because　of　the　fungicidal　effects　of　H2S.　Upon　drought,　H2S　fumigation　caused　stomata　closure,　which　resulted　in　a　lower　matric　suction　in　the　vegetated　soil　than　that　without　H2S　fumigation.　Accordingly,　H2S　concentration　reduced　because　of　oxidation　by　metal　oxides　in　soil.　Upon　subsequent　rainfall,　more　infiltration　but　lower　matric　suction　was　observed　in　vegetated　soils　than　that　in　bare　case,　whereas　H2S　concentration　decreased　continuously　due　to　gas　dissolution　in　the　pore　water.　Direct　application　of　laboratory　findings　herein　to　field　cases　should　be　used　with　cautions,　because　the　applied　continuous　lightening　and　low　evapotranspiration　rate　of　the　soil　column　tests　may　not　be　representative　to　field　conditions.　©　2023　Thomas　Telford　Ltd.