An apparatus for controlling unwanted vegetation and pests is disclosed. The apparatus comprises a reservoir (102), release means (106) connected to the reservoir (102), and a nozzle (110) for spraying a stream of foam including steam. A liquid comprising water and a surfactant is heated in the reservoir (102) to an elevated temperature and forms foam when discharged through the nozzle (110). The foam bubbles contain steam which is effective at killing the foliage. Steam pressure within the reservoir (102) is used to discharge the foam.
