The invention relates to a device for removing weed clumps from existing lawns. The device comprises a frame (1) holding a driven shaft (20), parallel to the lawn and perpendicular to the direction of movement, which is provided with discs (17) comprising cutting elements (17a). The frame (1) can be coupled to driving vehicle for moving the device across the ground in a direction of movement. The discs (17) with cutting elements (17a) are fixedly attached to the driven shaft (20) at an angle which is not perpendicular, but which may be adjustable. Also, the cutting direction of the cutting elements (17a) in the lawn substantially corresponds to the direction of movement. As a result thereof, the cutting elements which are distributed across the circumference of the discs (17), will cut short slots into the lawn at a small distance next to one another and pull out weed clumps. The speed of movement determines the distance between the cut slots of the same cutting element (17a), thus making it easy for the user to change the intensity of the operation.