Abstract: A plural-castor-mounted lightweight tubular frame has a central resilient housing-clamping mechanism adapted for holding a string trimmer having a tapered or other conventional-shape housing at a desired level for trimming weeds or grass. Mechanical advantage and threaded adjustment are provided by the clamping mechanism. The handle of the string trimmer is employed as the handle by which the castor mounted frame and the trimmer held in it are directed. Quick detach/quick attach features enable the string trimmer to be used conveniently by itself when desired. Two height-adjustment provisions can be used, a coarse adjustment of clamping-height, and a fine adjustment of threaded connection between threaded shanks of the castor and clamping nuts at the frame that also provides convenient tilt-adjustment of the string trimmer relative to the ground.