the assembly comprising an elongate outer member 12 in which an inner member 14 is deployed for sliding inner member 14 includes a toothed front edge formed as a row of spaced tooth projections 16 these teeth are aligned adjacent a similar set of teeth 18 formed on the front edge of member 12 each of which extends beyond the ends of teeth 16 thus the teeth 18 of the lower member 12 project to a further distance and accordingly are cut at a sharper or more acute notch angle as the notching of teeth 16 any particulate matter that may then be lodged on the teeth 18 will be laterally moved in response to the movement of teeth 16 as result the shearing assembly 11 is effective both to cut any lawn growth and to assist in the transport of the cut matter towards the screws hb1 and hb2 the rear edge of member 14 is rolled over as a fold 14a around the rear edge of member 12 this rolled over form further assists in the transfer of the cut debris into the screws hb1 and hb2 to effect a releasable attachment of the shearing assembly the lateral ends of the lower member 12 are provided with end tabs 22 and 24 which include slots 22a and 24a for fastener engagement to the housing h tab 24 moreover is useful to engage a spring 25 stretched from a tab 26 on a clamp 28 fixed to member 14 this clamp 28 fixes a push rod along member 14.