A portable apparatus 1 suitable for controlling vegetation comprising an insulated reservoir 2, release means 6 connected to the reservoir and a nozzle 10, for applying a stream of foam including steam, connected to the reservoir through the release means. The reservoir is provided with heating means 12 connected to mains power either directly or via a docking station. The reservoir is suitable for the steam pressure in the reservoir to be above atmospheric pressure. Further battery means may be provided for when the device is disconnected from mains power. The device may be handheld or mounted on a trolley. Liquid comprising water and a surfactant, i.e. a foaming agent, is heated in the reservoir to an elevated pressure and forms a foam when discharged through the nozzle. The foam contains steam, and is effective at killing the foliage. Alternatively the apparatus may be used to control pests by applying hot foam to pests located on vegetation or hot foam and steam to pests located on the ground.
