apparatus for killing unwanted vegetation using heated water comprises a refillable compressed air tank , a refillable water tank , a shut - off valve operably installed on a connection conduit between the compressed air tank and the water tank for select opening and closing of the conduit to respectively allow and prevent flow between the tanks , a flexible hose connected to the water tank , an applicator wand connected to the flexible hose opposite the water tank and comprising a rigid delivery conduit terminating at a discharge end of the applicator wand and a normally closed control valve on the applicator wand to selectively and temporarily open to control discharge of heated water from the water tank under air pressure from the air tank . the apparatus is used to inject heated water beneath a spot of ground surface from which unwanted vegetation has emerged