A method for control of vegetation at places where said vegetation is undesirable, said method comprising intense irradiation of the vegetation for one or several periods by light, of which at least 10% of the effect is ultra-violet light, the total irradiation dosage (joule/m.sup.2) exceeding a minimal value necessary for the intended vegetation control. An apparatus for performing the method comprises at least one light source directed towards the undesired vegetation and emitting at least 10% of its light discharge in the ultra-violet range, said apparatus comprising means which after discharge of an irradiation dosage surpassing the minimal value necessary for the intended vegetation control discontinue the treatment of the areas in question.